Showing papers on "Single domain published in 2003"

Dynamics of ferroelastic domains in ferroelectric thin films.

Abstract: Dynamics of domain interfaces in a broad range of functional thin-film materials is an area of great current interest. In ferroelectric thin films, a significantly enhanced piezoelectric response should be observed if non-180° domain walls were to switch under electric field excitation. However, in continuous thin films they are clamped by the substrate, and therefore their contribution to the piezoelectric response is limited. In this paper we show that when the ferroelectric layer is patterned into discrete islands using a focused ion beam, the clamping effect is significantly reduced, thereby facilitating the movement of ferroelastic walls. Piezo-response scanning force microscopy images of such islands in PbZr0.2Ti0.8O3 thin films clearly point out that the 90° domain walls can move. Capacitors 1 μm2 show a doubling of the remanent polarization at voltages higher than ∼15 V, associated with 90° domain switching, coupled with a d33 piezoelectric coefficient of ∼250 pm V−1 at remanence, which is approximately three times the predicted value of 87 pm V−1 for a single domain single crystal.

Switching of magnetization by nonlinear resonance studied in single nanoparticles.

Abstract: Magnetization reversal in magnetic particles is one of the fundamental issues in magnetic data storage. Technological improvements require the understanding of dynamical magnetization reversal processes at nanosecond time scales. New strategies are needed to overcome current limitations. For example, the problem of thermal stability of the magnetization state (superparamagnetic limit) can be pushed down to smaller particle sizes by increasing the magnetic anisotropy. High fields are then needed to reverse the magnetization, which are difficult to achieve in current devices. Here we propose a new method to overcome this limitation. A constant applied field, well below the switching field, combined with a radio-frequency (RF) field pulse can reverse the magnetization of a nanoparticle. The efficiency of this method is demonstrated on a 20-nm-diameter cobalt particle by using the microSQUID (superconducting quantum interference device) technique. Other applications of this method might be nucleation or depinning of domain walls.

Magnetic domain-wall dynamics in a submicrometre ferromagnetic structure.

Abstract: As fabrication technology pushes the dimensions of ferromagnetic structures into the nanoscale, understanding the magnetization processes of these structures is of fundamental interest, and key to future applications in hard disk drives, magnetic random access memory and other 'spintronic' devices1,2,3,4. Measurements on elongated magnetic nanostructures5,6 highlighted the importance of nucleation and propagation of a magnetic boundary, or domain wall, between opposing magnetic domains in the magnetization reversal process. Domain-wall propagation in confined structures is of basic interest7,8 and critical to the performance of a recently demonstrated magnetic logic scheme for spintronics9. A previous study of a 500-nm-wide NiFe structure obtained very low domain-wall mobility in a three-layer device10. Here we report room-temperature measurements of the propagation velocity of a domain wall in a single-layer planar Ni80Fe20 ferromagnetic nanowire 200 nm wide. The wall velocities are extremely high and, importantly, the intrinsic wall mobility is close to that in continuous films11, indicating that lateral confinement does not significantly affect the gyromagnetic spin damping parameter to the extreme extent previously suggested10. Consequently the prospects for high-speed domain-wall motion in future nanoscale spintronic devices are excellent.

Unusually high coercivity and critical single-domain size of nearly monodispersed CoFe2O4 nanoparticles

Abstract: Nearly monodispersed CoFe2O4 nanoparticles with average sizes between 8 and 100 nm were synthesized by using seed-mediated growth dominant coprecipitation and modified oxidation methods. X-ray diffraction and Mossbauer spectroscopy analyses confirmed the spinel phase and a stoichiometric composition of (Co0.25Fe0.75)[Co0.75Fe1.25]O4 for powders with different particle diameters. Rotational hysteresis loss (Wr) analysis showed an average switching field (Hp) of 17 kOe and a magnetic anisotropy field (Hk) of 38 kOe for the 40 nm CoFe2O4 particles. The corresponding magnetocrystalline anisotropy energy constant (K) was about 5.1×106 erg/cc. The Hc and Hp results suggest that the critical single-domain size of CoFe2O4 is about 40 nm. The room temperature coercivity (Hc) of the 40 nm CoFe2O4 particles is found to be as high as 4.65 kOe.

Coexistence of ferromagnetic and antiferromagnetic order in Mn-doped Ni2MnGa

Abstract: Ni-Mn-Ga is interesting as a prototype of a magnetic shape-memory alloy showing large magnetic-field-induced strains We present here results for the magnetic ordering of Mn-rich Ni-Mn-Ga alloys based on both experiments and theory Experimental trends for the composition dependence of the magnetization are measured by a vibrating sample magnetometer in magnetic fields of up to several tesla and at low temperatures The saturation magnetization has a maximum near the stoichiometric composition and it decreases with increasing Mn content This unexpected behavior is interpreted via first-principles calculations within the density-functional theory We show that extra Mn atoms are antiferromagnetically aligned to the other moments, which explains the dependence of the magnetization on composition In addition, the effect of Mn doping on the stabilization of the structural phases and on the magnetic anisotropy energy is demonstrated

Domain wall motion induced by spin polarized currents in ferromagnetic ring structures

Abstract: We present an experimental study of the influence of spin-polarized currents on the displacement of domain walls in submicrometer permalloy ring structures. Using magnetoresistance (MR) measurements with multiple nonmagnetic contacts, we can sense the displacement of a domain wall and, by injecting large dc current densities (1011 A/m2), we can increase or decrease the magnetic field needed to move a single domain wall, depending on the direction of the current with respect to the applied field direction. Using rings with and without notches and by measuring the MR with the magnetic field applied along different directions, we show that we can exclude the possibility that the dominating effect is a classical Oersted field. We conclude that our observations can be explained by a directional spin torque effect.

Single-domain properties of 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 single crystals under electric field bias

Abstract: We report a complete set of material properties of single-domain, relaxor-based 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 [PMN–33%PT] single crystals. Because the single-domain state is unstable in natural conditions, a bias electric field of 0.2 MV/m was applied along the dipole direction of the rhombohedral phase during the measurements. It was found that the electromechanical coupling coefficient k33 and the piezoelectric constant d33 for single-domain PMN–33%PT are 69% and 190 pC/N, respectively. Both of them are much smaller than those of multidomain PMN–33%PT poled along [001] direction. However, the shear piezoelectric constant d15 of single-domain PMN–33%PT reaches 4100 pC/N, which is much higher than that of multidomain PMN–33%PT.

First-order-reversal-curve (FORC) diagrams for pseudo-single-domain magnetites at high temperature

Abstract: The recently developed first-order reversal curve (FORC) technique for rapidly examining magnetic domain state has great potential for paleomagnetic and environmental magnetic investigations. However, there are still some gaps in the basic understanding of FORC diagrams, in particular the behavior of pseudo-single-domain (PSD) grains and the contribution of magnetostatic interactions. In this paper we address some of these problems. We report the first FORC diagrams measurements on narrowly sized and well-characterized synthetic PSD through multidomain (MD) magnetite samples. The FORC diagrams evolve with grain size from single-domain (SD)-like to MD-like through the PSD grain size range. Since each sample contains grains of essentially a single size, individual PSD grains evidently contain contributions from both SD-like and MD-like magnetic moments, in proportions that vary with grain size; the evolving FORC diagrams cannot be due to physical mixtures of SD and MD grains of widely different sizes. The FORC diagrams were all asymmetric. Small PSD samples have FORC diagrams with a distinctive closed-contour structure. The distributions of the larger MD grains display no peak, and lie closer to the interaction-field axis. To assess the effect of magnetostatic interactions, we measured FORC diagrams between room temperature and the Curie temperature. On heating the FORC distributions contract without changing shape until ∼500°C. Above this temperature the diagrams become more MD-like, and in addition become more symmetric. The temperature dependence of the interaction-field parameter is proportional to that of the saturation magnetization, in accordance with Neel’s interpretation of the Preisach diagram. The decrease in asymmetry with heating suggests that the origin of the asymmetry lies in magnetostatic interactions. The magnetic hysteresis parameters as a function of temperature were determined from the FORC curves. As the grain size decreased the normalized coercive force was found to decrease more rapidly with temperature.

Kerr observations of asymmetric magnetization reversal processes in CoFe/IrMn bilayer systems

Abstract: The magnetization reversal process in the ferromagnetic layer of an exchange-biased Co90Fe10(20 nm)/Ir23Mn77(10 nm) film structure, deposited by dc-magnetron sputtering, is imaged by high-resolution Kerr microscopy. Additionally, high-resolution magnetization loops are measured by deriving the magnetization signal from the average image intensity. The magnetization reversal occurs first by magnetization rotation under the development of ripple-like structures. The modulated structures then partially switch, generating complicated multidomain configurations, which finally annihilate by large angle domain wall movement. The amount of magnetization rotation at different field directions is quantified by measuring the transversal magnetization components during reversal. A strong asymmetry, both in domain behavior and magnetization loop, between the forward and recoil branch of the magnetization reversal is found. The magnitude of asymmetry strongly depends on small angle misalignments between the direction o...

Synthesis and aging effect of spherical magnetite (Fe3O4) nanoparticles for biosensor applications

Abstract: The chemical coprecipitation process was used to synthesize about 7 nm, spherical magnetite nanoparticles to study magnetic properties and the aging effect. As-produced spherical magnetite nanoparticles have been aged in the atmosphere for 19 months. Magnetic properties and aging effect were studied by Mossbauer spectroscopy at a temperature ranging from 77 to 300 K, vibrating sample magnetometer, and x-ray diffraction. Saturation magnetization and coercivity were found to be 49 emu/g and nearly 0 Oe at room temperature, respectively. A singlet Mossbauer spectrum was observed at room temperature, implying superparamagnetic behavior of the particles, while a two-sextet spectrum was observed at 77 K. The particle size in this study is about 7 nm, which is smaller than the superparamagnetic size of 26 nm as calculated from Neel’s theory of single domain particles. After having aged these particles for 19 months, all magnetic properties and their original shapes were retained. Superparmagnetic magnetite nanoparticles synthesized in this study can be applied to microbead applications of a biosensor.

Effect of magnetostatic interactions on the hysteresis parameters of single‐domain and pseudo‐single‐domain grains

Abstract: [1] From experiments it is known that magnetostatic interactions between grains strongly affect the magnetic behavior of samples. However, because of the difficulty in predicting the nonlinear behavior, the effect of interactions has been largely ignored from theoretical models. Instead models are often based on noninteracting assemblages. This approximation is valid for certain natural systems, but there are many cases where interactions are known to be important, for example, bacterial magnetosomes found in sedimentary rocks. Using a three-dimensional micromagnetic model, we have conducted a detailed study of the role of magnetostatic interactions on the magnetic properties of assemblages of ideal single domain (SD) grains and cubic grains between 30–250 nm in size. We quantify the contribution of interactions to hysteresis parameters and the Day plot. We show that interactions can strongly affect the magnetic characteristics of a grain assemblage. For example, assemblages of interacting SD grains can plot in the traditional multidomain (MD) area of the Day plot. For grains >100 nm in size, interactions can have the opposite effect, and can cause the hysteresis parameters to shift toward the SD region of the Day plot. In addition to varying grain size, we have also considered various anisotropies, e.g., uniaxial and cubic, and the importance of the alignment configuration of the particle assemblages, i.e., randomly distributed or aligned. It is shown that for assemblages of aligned magnetite particles, that as the interaction spacing is decreased, the SD/MD transition size increases, which may explain why some magnetotatic bacteria possess aligned grains of magnetite above the traditional transition size value of 70 nm. By aligning the anisotropies, the grains become stable SD, and having larger crystals will increase the magnetic signal.

An integrated study of the grain‐size‐dependent magnetic mineralogy of the Chinese loess/paleosol and its environmental significance

Abstract: [1] To investigate the grain-size-dependent properties of the magnetic minerals in Chinese loess/paleosol samples (Touxiangdao, Xining, Qinghai province, China), magnetic extracts were divided into two size fractions by gravitational settling. On the basis of hysteresis measurements, thermal demagnetization of low-temperature saturation isothermal remanent magnetization, and nonmagnetic studies (SEM and XRD) we identified magnetic phases both in the grain size fractions of the magnetic extracts and in the less magnetic residues to provide more accurate and complete descriptions of all the magnetic components in the bulk natural samples. The results show that the oxidation degree (nonstoichiometry) of magnetic minerals is strongly affected by both grain size and the paleoclimatic environment in which they were deposited and altered. In ascending order of the oxidation degree of our samples, we find (1) loess-coarse particles (LC) are multidomain (MD) magnetite with slight oxidation, (2) paleosol-coarse (PC) particles are also MD magnetite but with a higher oxidation degree compared to LC, (3) loess-fine (LF) particles are pseudo-single domain (PSD) magnetite with a high oxidation degree, and (4) paleosol-fine (PF) particles are PSD maghemite. Single domain (SD) and superparamagnetic (SP) maghemite mainly stay in the residues. Further thermomagnetic analysis of PF (PSD maghemite) revealed that this natural maghemite has a Curie temperature identical to that of magnetite and that the conversion efficiency of transformation from maghemite to hematite is only about 50% after a 700°C heating/cooling cycle. These new results identify the sources of multicomponent NRM in Chinese loess sequences as well as clarify the paleoenviromental and paleoclimatic controls on the remanence components.

Relation between structure, magnetization process and magnetic shape memory effect of various martensites occurring in Ni-Mn-Ga alloys

Abstract: Magnetic properties and magnetic shape memory effect of three Ni-Mn-Ga alloys representing three different martensitic phases; five-layered tetragonal (5M), seven-layered orthorhombic (7M), and non-modulated tetragonal (NM) martensite were studied at room temperature. Magnetization process occurs mostly by magnetization rotation. Magnetic anisotropy energy is high for all three phases ranging from 1.1 to 1.7×10 5 J/m 3 . The direction of short lattice constant is always a direction of easy magnetization. It is demonstrated that the high magnetic anisotropy and low twinning stress render a MSM effect possible in 5M and 7M martensite. The 5M martensite exhibits more than 6% field induced strain. The giant strain is followed by large magnetization jump. Simultaneous measurement of magnetization changes and field-induced strain as a function of magnetic field demonstrates the nature of the magnetic shape memory effect and validates the proposed mechanism.

Dynamics of a magnetic domain wall in magnetic wires with an artificial neck

Abstract: Magnetization reversal in submicron magnetic wires consisting of a NiFe/Cu/NiFe trilayer with an artificial neck was investigated by utilizing the giant magnetoresistance effect. A magnetic domain wall was injected into the wire by a local magnetic field applied at the end of the wire. Pinning and depinning of the magnetic domain wall were detected as sharp changes in resistance. It was found that the neck works as a pinning site of a domain wall and that the depinning field increases with a decrease of the neck width.

Uniaxial magnetic anisotropy and magnetic switching in La0.67Sr0.33MnO3 thin films grown on vicinal SrTiO3(100)

Abstract: La0.67Sr0.33MnO3 ultrathin films grown on vicinal SrTiO3(100) surface show an in-plane uniaxial magnetic anisotropy with easy axis along the substrate atomic steps generated by a 10° miscut off the (100) plane. Over a large angular range, the angular dependence of magnetic switching field is found to obey the 1/cos φ law, indicating that the magnetic reversal is completed by a 180° domain nucleation and sweeping along the easy axis. However, when the applied field is perpendicular to the hard axis (φ=90°), the magnetization reversal is found to be well described by the Stoner–Wohlfarth model, in which the magnetization coherently rotates from the easy axis to hard axis.

Morphology and domain pattern of L10 ordered FePt films

Abstract: Magnetic force microscope (MFM) was used to characterize the L10 ordered FePt(001) films sputter deposited directly on MgO(001) substrates at an elevated temperature. With the change of nominal thickness (tN), the morphology varied from isolated particles to continuous films. The coercivity showed a marked change at the percolation boundary of tN≅45 nm, where the film morphology changed from a discontinuous to a continuous state. Below tN=45 nm, the coercivity did not change apparently, though the number of single-domain particles increased gradually with decreasing tN. At tN=20 nm, a critical (maximum) size of single domain particles, d=180 nm, was obtained from a size distribution, which was taken from the atomic force microscope/MFM measurement. The value calculated for this critical size was found to be d=155 nm in the assumption that the particles had ellipsoidal shape. The slight difference between experimental and theoretical values is likely to be attributed to an axis ratio (c/a) distribution of ...

Direct observation of the single-domain limit of Fe nanomagnets by spin-polarized scanning tunneling spectroscopy.

Abstract: We have investigated the magnetic structure of self-organized Fe islands on W(001) by means of spin-polarized scanning tunneling spectroscopy (Sp-STS). Single-domain, simple vortex, and distorted vortex states have been observed. The high resolution magnetic images were used to experimentally determine the single-domain limit. The experimental structures were compared with results of micromagnetic calculations confirming the ground state nature of the experimental configurations. The single-domain limit directly observed with Sp-STS is consistent with theoretical predictions.

Magnetic dynamics of single-domain Ni nanoparticles

Abstract: The dynamic magnetic properties of Ni nanoparticles diluted in an amorphous SiO2 matrix prepared from a modified sol–gel method have been studied by the frequency f dependence of the ac magnetic susceptibility χ(T). For samples with similar average radii ∼3–4 nm, an increase of the blocking temperature from TB∼20 to ∼40 K was observed for Ni concentrations of ∼1.5 and 5 wt %, respectively, assigned to the effects of dipolar interactions. Both the in-phase χ′(T) and the out-of-phase χ″(T) maxima follow the predictions of the thermally activated Neel–Arrhenius model. The effective magnetic anisotropy constant Keff inferred from χ″(T) vs f data for the 1.5 wt % Ni sample is close to the value of the magnetocrystalline anisotropy of bulk Ni, suggesting that surface effects are negligible in the present samples. In addition, the contribution from dipolar interactions to the total anisotropy energy Ea in specimens with 5 wt % Ni was found to be comparable to the intrinsic magnetocrystalline anisotropy barrier.

Multidomain to single-domain transition for uniform Co80Ni20 nanoparticles

Abstract: Uniform fine Co80Ni20 particles with diameters between 18 and 540 nm have been synthesized by polyol reduction of metallic salts. Their magnetic properties have been studied as a function of the particle size at 10 and 300 K. From the analysis of the experimental results at room temperature, a transition from polydomain structure to single-domain structure with the reduction of the particle size to around 40 nm is deduced. A considerable decrease of the saturation magnetization with respect to the bulk value has been found as the particle size decreases at both measuring temperatures. At low temperature, a strong increase of coercivity has been observed which is ascribed to an enhancement of the effective magnetic anisotropy induced by the surface layer.

Size-independent spin switching field using synthetic antiferromagnets

Abstract: The arrays of the synthetic antiferromagnetic (SyAF) patterned bits consisting of Co90Fe10 (t1nm)/Ru (d nm)/Co90Fe10 (t2 nm) were successfully fabricated with micron to submicron sizes and different aspect ratios. Magnetization switching field Hsw and magnetic domain structure were investigated using magneto-optical Kerr effect and magnetic force microscopy (MFM), respectively. It was demonstrated that the strongly AF-coupled SyAF with aspect ratio k=1 creates size-independent Hsw down to submicron sizes fabricated, which is understood by zero demagnetization field for k=1 and single domain structure, observed by MFM. The size-independent switching field demonstrates the predominance of the SyAF for spintronics devices, requiring a low switching field and stabilized single domain structure for small bit sizes such as ultrahigh density magnetic random access memories and spin transistors.

Penetration of vortices into the ferromagnet'type-II superconductor bilayer

Abstract: Vortex structures in the ferromagnet/type-II superconductor bilayer are investigated when the ferromagnet has domain structure and perpendicular magnetic anisotropy. It is found that two equilibrium vortex structures can be realized: straight vortices with alternating directions corresponding to the direction of the magnetization in the ferromagnetic domains and vortex semiloops connecting the ferromagnetic domains with opposite direction of the magnetization. These states are separated by an energy barrier. The values of the critical magnetization for the formation of these vortex structures are determined.

Hysteresis curve of magnetic nanocrystals monolayers: Influence of the structure

Abstract: We calculate the magnetization curve at vanishing temperature of a monolayer of spherical single domain magnetic nanocrystals in terms of the structure of the monolayer. The magnetization curve of a square lattice of particles is compared to those of disordered monolayers. The particles on the disordered monolayers are either distributed isotropically on the surface or organized in chains, which are either linear and or totally flexible. A strong effect of the structure is found only in the case of linear chains and when the magnetization is measured along the chains direction. In the experimental part a monolayer of cobalt nanoparticles organized in a chainlike structure is elaborated by applying a magnetic field during the evaporation of a ferrofluid on a substrate. The change of the magnetization curve due to the chainlike structure is compared to that of the model.

Construction of hysteresis loops of single domain elements and coupled permalloy ring arrays by magnetic force microscopy

Abstract: Magnetic structure and magnetization reversal of permalloy ring arrays and elongated permalloy particle array were studied by magnetic force microscopy (MFM). For single domain permalloy particles, the hysteresis loop is constructed by counting the percentage of switched elements imaged at remanence. For permalloy ring elements, two different states are energetically stable: a vortex state and an onion state. Their hysteresis loop is obtained by MFM imaging at a field between the switching fields of these two states. The magnetostatic coupling among these ring elements is directly revealed.

Introduction of thermal activation in forward modeling of hysteresis loops for single‐domain magnetic particles and implications for the interpretation of the Day diagram

Abstract: [1] Synthetic hysteresis loops were generated by numerically solving the classical Stoner-Wohlfarth model and a thermally activated Stoner-Wohlfarth model for a set of randomly oriented magnetic grains. Although computationally intensive this method allows forward modeling of hysteresis loops of single-domain (SD) and viscous grains. In the classic Stoner-Wohlfarth model the shape of the modeled loops can be modified by changing the distribution of the anisotropy energy but all the loops will all have similar hysteresis parameters M sr /M s and H cr /H c corresponding to that of a theoretical assemblage of SD particles. The thermally activated Stoner-Wohlfarth model, which allows the magnetic moment of each grain to switch between two energy minima according to Boltzmann statistics, extends the SD model toward superparamagnetic (SP) grains and introduces a volume dependency. Numerical simulation using the thermally activated model shows that the shapes of SD loops are modified by the effect of the thermal energy if the particles are sufficiently small. The major effect of the thermal disturbance is observed in highly viscous particles (smaller than approximately 0.03 μm in diameter, for magnetite) where it strongly reduces the coercivity and to a lesser extent the remanent magnetization. The effect on the hysteresis parameters is a large increase in H cr /H c and a decrease in M sr /M s , by factors that vary with anisotropy distribution, grain volume and measurement time. For certain grain sizes, these result in hysteresis parameters that are similar to those attributed to pseudosingle-domain (PSD) grains.

Structural and magnetic properties of nanocrystalline Zn0.65Ni0.35Fe2O4 powder obtained from heteropolynuclear complex combination

Abstract: The nanocrystalline Zn0.65Ni0.35Fe2O4 mixed ferrite with a mean diameter between 37.0 and 68.1 nm was obtained from the heteropolynuclear complex combination Fe2(Zn,Ni)(OH)4(C2H2O4)2·nH2O, having as ligand the C2H2O42− glyoxylate dianion. The thermal decomposition process of the complex combination was investigated by DTA–TG techniques. After thermal decomposition at 350 °C, the resulting ‘residue’, composed of a quasi-amorphous mixture of oxides, was annealed for 2 h within the 900–1300 °C temperature range. By X-ray diffraction (XRD), it was shown that the resulting powder was made up of a single phase of Zn–Ni ferrite nanocrystals with fcc structure and a lattice constant in agreement with the known value. The magnetic measurements showed the increase of the specific saturation magnetization σs as well as the decrease in both coercivity Hc and remanence ratio r of the nanocrystallites with the increase of the annealing temperature. This behavior was correlated with the increase of the mean diameter of the nanocrystallites above a critical value (dcr), (under this critical value the particles can be considered as single domain). The model calculation for the critical diameter is in agreement with the experimental results.

Critical thickness for high-remanent single-domain configurations in square ferromagnetic thin platelets

Abstract: By means of three-dimensional micromagnetic finite element modeling, zero-field magnetization patterns of ferromagnetic thin film elements of square shape are simulated and energetically compared The geometry of the sample (edge length $a,$ thickness $D)$ and its intrinsic material parameters (hardness $Q)$ are systematically varied Based on the results the corresponding phase diagram is set up which identifies a quasihomogeneous single-domain phase (C, S, and flower states) and a vortex phase (Landau state) For the transition between the two phases a material- and edge-length-dependent critical film thickness is found The numerical results can be confirmed qualitatively using a simple analytical model calculation

Origin of the Giant Piezoelectric Properties in the [001] Domain Engineered Relaxor Single Crystals

Abstract: Relaxor single crystals PZN–9%PT have been cut and poled along [101] direction for which the spontaneous polarization Ps is approximately parallel to the poling field Ep The piezoelectric matrix of the monoclinic single-domain (1M state) has been determined, in the approximation of an orthorhombic symmetry The shear mode (15) along [101], gives the highest electromechanical coupling factor k15 (>80%) and the largest piezoelectric coefficient d15 (~3200 pC/N) The properties of the disoriented 1M state have been calculated from a change of axes The maximum of d33θ is obtained along a direction close to [001] This is due to the very large value of d15 compared to d33 in the basic 1M state On the other hand the transverse piezoelectric coefficient along [uv0] for the [001] disoriented Ps single domain presents a strong anisotropy Finally, in the [001] domain engineered configuration, an important extrinsic contribution of the domain coexistence is evidenced by comparing calculated and measured coefficients