Showing papers on "Magnetic structure published in 2009"
TL;DR: This study experimentally establishes magnetic materials lacking inversion symmetry as an arena for new forms of crystalline order composed of topologically stable spin states in the chiral itinerant-electron magnet MnSi.
Abstract: Skyrmions represent topologically stable field configurations with particle-like properties. We used neutron scattering to observe the spontaneous formation of a two-dimensional lattice of skyrmion lines, a type of magnetic vortex, in the chiral itinerant-electron magnet MnSi. The skyrmion lattice stabilizes at the border between paramagnetism and long-range helimagnetic order perpendicular to a small applied magnetic field regardless of the direction of the magnetic field relative to the atomic lattice. Our study experimentally establishes magnetic materials lacking inversion symmetry as an arena for new forms of crystalline order composed of topologically stable spin states.
3,651 citations
TL;DR: The unusual magnetism exhibited by dysprosium triangles [Dy3(μ3-OH)2L3Cl2(H2O)4] is explained using the recently developed ab initio methodology for the simulation of magnetic properties of complexes as mentioned in this paper.
Abstract: The unusual magnetism exhibited by dysprosium triangles [Dy3(μ3-OH)2L3Cl2(H2O)4][Dy3(μ3-OH)2L3Cl(H2O)5]Cl5·19H2O is explained using the recently developed ab initio methodology for the simulation of magnetic properties of complexes The local anisotropy axes on the dysprosium sites are found to lie in the plane of the Dy3 triangle and to make angles of ca 120° with each other The small antiferromagnetic exchange interaction between sites leads to a non-magnetic Kramers doublet in the ground state of the complex The arrangement of the local magnetization vectors in this state is close to toroidal By contrast, the lowest excited states are characterized by a huge magnetic moments of ca 20 μB and show very different behavior of magnetization for fields applied along and perpendicular to the plane of the Dy3 triangle
305 citations
TL;DR: In this paper, the epitaxial growth and magnetic properties of Mn2.5Ga thin films, which were deposited on Cr/MgO single crystal substrates by magnetron sputtering, were reported.
Abstract: We report on epitaxial growth and magnetic properties of Mn2.5Ga thin films, which were deposited on Cr/MgO single crystal substrates by magnetron sputtering. X-ray diffraction results revealed the epitaxial relationships as Mn2.5Ga(001)[100]∥Cr(001)[110]∥MgO(001)[100]. The presence of (002) and (011) superlattice peaks indicates that the films were crystallized into DO22 ordered structures. The perpendicular magnetic anisotropy (PMA) properties were found to be related to the extent of DO22 chemical ordering. A giant PMA (Kueff=1.2×107 erg/cm3) and low saturation magnetization (Ms=250 emu/cm3) can be obtained for the film with highest chemical ordering parameter (S=0.8).
191 citations
TL;DR: In this paper, the bulk and surface properties of spinel oxide Co3O4 have been investigated and the bulk magnetic structure is calculated to be antiferromagnetic, with a Co2+ moment of 2.631 μB.
157 citations
Patent•
03 Sep 2009TL;DR: A method and system for providing a magnetic structure in magnetic transducers is described in this paper, where the magnetic structure includes a pinned layer, a non-magnetic spacer layer, and a free layer.
Abstract: A method and system for providing a magnetic structure in magnetic transducer is described. The magnetic structure includes a pinned layer, a nonmagnetic spacer layer, and a free layer. The nonmagnetic spacer layer is between the pinned layer and the free layer. The free layer includes a first magnetic layer, a second magnetic layer, and a magnetic insertion layer between the first magnetic layer and the second magnetic layer. The first magnetic layer has a first magnetostriction. The second magnetic layer has a second magnetostriction opposite to the first magnetostriction. The magnetic insertion layer provides a growth texture barrier between the first magnetic layer and the second magnetic layer.
141 citations
TL;DR: In this paper, the authors identify the phase lines corresponding to transitions among the ambient-pressure paramagnetic tetragonal (T), the antiferromagnetic orthorhombic (O), and the nonmagnetic collapsed tetragon (cT) phases of a single-crystal neutron and high-energy x-ray diffraction.
Abstract: Single-crystal neutron and high-energy x-ray diffraction measurements have identified the phase lines corresponding to transitions among the ambient-pressure paramagnetic tetragonal (T), the antiferromagnetic orthorhombic (O), and the nonmagnetic collapsed tetragonal (cT) phases of ${\text{CaFe}}_{2}{\text{As}}_{2}$. We find no evidence of additional structures for pressures of up to 2.5 GPa (at 300 K). Both the T-cT and O-cT transitions exhibit significant hysteresis effects, and we demonstrate that coexistence of the O and cT phases can occur if a nonhydrostatic component of pressure is present. Measurements of the magnetic diffraction peaks show no change in the magnetic structure or ordered moment as a function of pressure in the O phase, and we find no evidence of magnetic ordering in the cT phase. Band-structure calculations show that the transition into the cT phase results in a strong decrease in the iron $3d$ density of states at the Fermi energy, consistent with a loss of the magnetic moment.
139 citations
TL;DR: In this article, a single crystal neutron diffraction study was carried out to determine the magnetic structure of EuFe2As2 and investigate the coupling of two magnetic sublattices.
Abstract: Among various parent compounds of iron pnictide superconductors, EuFe2As2 stands out due to the presence of both spin density wave of Fe and antiferromagnetic ordering (AFM) of the localized Eu2+ moment. Single crystal neutron diffraction studies have been carried out to determine the magnetic structure of this compound and to investigate the coupling of two magnetic sublattices. Long range AFM ordering of Fe and Eu spins was observed below 190 K and 19 K, respectively. The ordering of Fe2+ moments is associated with the wave vector k = (1,0,1) and it takes place at the same temperature as the tetragonal to orthorhombic structural phase transition, which indicates the strong coupling between structural and magnetic components. The ordering of Eu moment is associated with the wave vector k = (0,0,1). While both Fe and Eu spins are aligned along the long a axis as experimentally determined, our studies suggest a weak coupling between the Fe and Eu magnetism.
131 citations
TL;DR: In this paper, the physical origin of a magnetic dead layer (MDL) in manganite nanoparticles was investigated and it was shown that the internal magnetic structure of the MDL is constituted by small ferromagnetic clusters in a frustrated configuration.
Abstract: We present experimental evidence on the physical origin of a magnetic dead layer (MDL) in manganite nanoparticles. The studied nanoparticles constitute the wall of La0.67Sr0.33MnO3 and La0.67Ca0.33MnO3 manganite nanotubes. Magnetic properties analysis and high resolution transmission electron microscopy show a shell of approximately 2 nm thickness with different properties from the core. In this shell the atoms are in a noncrystalline array that perfectly explains the 50% reduction of the magnetization compared to the bulk. Moreover, we present experimental evidence that the internal magnetic structure of the MDL is constituted by small ferromagnetic clusters in a frustrated configuration.
122 citations
TL;DR: High-resolution neutron diffraction and inelastic neutron scattering experiments in the frustrated multiferroic hexagonal compounds RMnO_{3} (R = Ho,Yb,Sc,Y), which provide evidence of a strong magnetoelastic coupling in the whole family.
Abstract: We have performed high-resolution neutron diffraction and inelastic neutron scattering experiments in the frustrated multiferroic hexagonal compounds RMn0 3 (R = Ho, Yb, Sc, Y), which provide evidence of a strong magnetoelastic coupling in the whole family. We can correlate the atomic positions, the type of magnetic structure, and the nature of the spin waves whatever the R ion and temperature. The key parameter is the position of the Mn ions in the unit cell with respect to a critical threshold of 1/3, which determines the sign of the coupling between Mn triangular planes.
116 citations
TL;DR: In this article, the authors review neutron scattering investigations of the crystal structures, magnetic structures, and spin dynamics of the iron-based RFe(As, P)(O, F) (R = La, Ce. Pr, Nd), (Ba,Sr, Ca)Fe2As2, and Fe1+x(Te-Se) systems.
Abstract: We review neutron scattering investigations of the crystal structures, magnetic structures, and spin dynamics of the iron-based RFe(As, P)(O, F) (R = La, Ce. Pr, Nd), (Ba,Sr,Ca)Fe2As2, and Fe1+x(Te-Se) systems. On cooling from room temperature all the undoped materials exhibit universal behavior, where a tetragonal-to-orthorhombic/monoclinic structural transition Occurs, below which the systems become antiferromagnets. For the first two classes of materials the magnetic structure within the a-b plane consists of chains of parallel Fe spins that are coupled antiferromagnetically in the orthogonal direction, with an ordered moment typically less than one Bohr magneton. Hence these are itinerant electron magnets, with a spin structure that is consistent with Fermi-surface nesting and a very energetic spin wave bandwidth similar to 0.2 eV. With doping, the structural and magnetic transitions are suppressed in favor of superconductivity, with Superconducting transition temperatures up to approximate to 55 K. Magnetic correlations are observed in the Superconducting regime, With a Magnetic resonance that follows the Superconducting order parameter just like the cuprates. The rare earth moments order antiferromagnetically at low T like 'conventional' Magnetic Superconductors, while the Cc crystal field linewidths are affected when superconductivity sets in. The application of pressure in CaFe2As2 transforms the system from a magnetically ordered orthorhombic material to a 'collapsed' non-magnetic tetragonal system. Tetragonal Fe1+xTe transforms to a low T monoclinic structure at small x that changes to orthorhombic at larger x, which is accompanied by a crossover from commensurate to incommensurate magnetic order. Se doping Suppresses the magnetic order, while incommensurate magnetic correlations are observed in the superconducting regime. (C) 2009 Elsevier B.V. All rights reserved.
108 citations
TL;DR: In this paper, the parsec-scale Faraday rotation measure (RM) distribution of six 'blazars' (0954+658, 1156+295, 1418+546, 1749+096, 2007+777 and 2200+420) are investigated using multifrequency (4.6, 5.1, 7.9, 8.9 and 15.4, 22 and 43 GHz) polarization observations with the American Very Long Baseline Array taken on 2006 July 2.
Abstract: The parsec-scale Faraday rotation measure (RM) distribution of six 'blazars' (0954+658, 1156+295, 1418+546, 1749+096, 2007+777 and 2200+420) are investigated using multifrequency (4.6, 5.1, 7.9, 8.9, 12.9, 15.4, 22 and 43 GHz) polarization observations with the American Very Long Baseline Array taken on 2006 July 2. Analysis of the RM provides the direction of the line-of-sight (LoS) magnetic field component, as well as the intrinsic (unrotated) two-dimensional polarization distribution on the plane of the sky. Our results show that the magnitude of the core RM increases systematically with frequency, and is well described by a power law, where |RM core | ∝ v a . Our measured values of a vary from 0.9 to 3.8, providing information on the assumed power-law fall-off in the electron density (n e ) with distance from the central engine (r) for each source. RM gradients were detected across the jets of 0954+658, 1156+295 and 1418+546, supporting the presence of helical magnetic fields in a sheath or boundary layer surrounding their jets. We find a bi-modal distribution of the intrinsic jet polarization orientation, with the polarization angles either aligned or orthogonal to the jet direction. The polarization of 2200+420 displays a continuous structure, with the polarization angles remaining aligned with the jet direction even as it bends. This indicates that the magnetic field structure in the synchrotron emitting plasma is dominated by an ordered transverse component. A helical magnetic field geometry can neatly explain both the bi-model distribution of the jet polarization orientation and the ordered polarization structure on these scales. For 0954+658, 1418+546 and 2200+420, we find that the core RM changes sign with distance from the central engine. We provide an explanation for this by considering a boundary layer of Faraday rotating material threaded by a helical magnetic field, where bends in the relativistic jet or accelerating/decelerating flows give rise to changes in the dominant LoS components of the magnetic field, which in turn gives rise to different signs of the RM.
TL;DR: In contrast to the closely related AFe2As2 (A = Ca, Sr, Ba, Eu) compounds, no structural distortion is observed in the magnetically ordered state of BaMn2A2.
Abstract: Neutron diffraction measurements have been performed on a powder sample of BaMn2As2 over the temperature T range from 10 K to 675 K. These measurements demonstrate that this compound exhibits collinear antiferromagnetic ordering below the Neel temperature T_N = 625(1) K. The ordered moment mu = 3.88(4) mu_B/Mn at T = 10 K is oriented along the c axis and the magnetic structure is G-type, with all nearest-neighbor Mn moments antiferromagnetically aligned. The value of the ordered moment indicates that the oxidation state of Mn is Mn^{2+} with a high spin S = 5/2. The T dependence of mu suggests that the magnetic transition is second-order in nature. In contrast to the closely related AFe2As2 (A = Ca, Sr, Ba, Eu) compounds, no structural distortion is observed in the magnetically ordered state of BaMn2As2.
TL;DR: In this paper, a detailed examination of the magnetic structure of anhydrous cupric chloride was carried out by powder neutron diffraction, magnetic susceptibility, and specific heat measurements on polycrystalline and single-crystal samples as well as an evaluation of the spin-exchange interactions by first-principles density-functional theory (DFT) calculations.
Abstract: We report a detailed examination of the magnetic structure of anhydrous cupric chloride ${\text{CuCl}}_{2}$ carried out by powder neutron diffraction, magnetic susceptibility, and specific heat measurements on polycrystalline and single-crystal samples as well as an evaluation of the spin-exchange interactions by first-principles density-functional theory (DFT) calculations. Anhydrous ${\text{CuCl}}_{2}$ shows one-dimensional antiferromagnetic behavior and long-range antiferromagnetic ordering below a N\'eel temperature of 23.9 K. Neutron powder and single-crystal diffraction reveal that, below 23.9 K, ${\text{CuCl}}_{2}$ undergoes a phase transition into an incommensurate magnetic structure [propagation vector (1,0.2257,0.5) with a spin spiral propagating along $b$ and the moments confined in the $bc$ crystallographic plane]. Our DFT calculations show that the spin spiral results from competing ferromagnetic nearest-neighbor and antiferromagnetic next-nearest-neighbor spin-exchange interactions along the spin chains. Implications for possible multiferroic behavior of ${\text{CuCl}}_{2}$ are discussed.
TL;DR: In this article, a combined Rietveld refinement, based on neutron and X-ray powder diffraction data simultaneously, for the three phases LiCoPO4, LizCoPO 4 with a specific intermediate Li-content z = 0.60(10) and CoPO4 was determined.
TL;DR: This work explains the Goodenough-Kanamori rules to the excited state of LaMnO(3), and notes that charge transfer can invert the sign of the semicovalent exchange interaction, which in turn perturbs the equilibrium bond lengths.
Abstract: Coherent lattice vibrations are excited and probed with pulses of 10 fs duration in LaMnO(3). The measured frequencies correspond to those of Jahn-Teller stretching and of out-of phase rotations of the oxygen octahedra. Surprisingly, the amplitude and damping rate of both modes exhibit a sharp discontinuity at the Neel temperature, highlighting nontrivial coupling between light, lattice, and magnetic structure. We explain this effect by applying the Goodenough-Kanamori rules to the excited state of LaMnO(3), and note that charge transfer can invert the sign of the semicovalent exchange interaction, which in turn perturbs the equilibrium bond lengths.
TL;DR: This work investigates the electronic structure and magnetic properties of Fe_{1+x}Te using first-principles density functional calculations and finds the calculated magnetic interactions are found to be critically dependent on doping and notably different from the arsenides.
Abstract: To understand newly discovered superconductivity in Fe-based systems, we investigate the electronic structure and magnetic properties of Fe_{1+x}Te using first-principles density functional calculations. While the undoped FeTe has the same Fermi surface nested at (pi,pi) as in Fe arsenides, doping by approximately 0.5 electrons reveals a novel square-type Fermi surface showing a strong (pi,0) nesting and leading to a different magnetic structure. Our result strongly supports the same mechanism of superconductivity in chalcogenides as in the arsenides, reconciling theory with existing experiments. The calculated magnetic interactions are found to be critically dependent on doping and notably different from the arsenides.
TL;DR: The outermost member of the 112 family LaBaCo2O5.5 has been synthesized using a multistep method to stabilize its structure as discussed by the authors, and its structural study, combining neutron powder diffraction and electron microscopy, shows that its orthorhombic matrix consists of layers of corner-shared CoO6 octahedra interconnected through CoO5 pyramids.
Abstract: The outermost member of the 112 family LaBaCo2O5.5 has been synthesized using a multistep method to stabilize its structure. Its structural study, combining neutron powder diffraction and electron microscopy, shows that its orthorhombic matrix consists of layers of corner-shared CoO6 octahedra interconnected through CoO5 pyramids like in the other 112 cobaltates but contains small LaBaMn2O5.5-type domains (8%) due to local oxygen displacement. Its magnetic properties and magnetic structure evidence the following features: G-type antiferromagnetic/G-type ferrimagnetic/paramagnetic with TN = 260 K and TC = 326 K. This cobaltate differs from other 112 cobaltates by its antiferromagnetic structure which keeps the same symmetry as its ferrimagnetic phase, probably due to the size effect of La3+ upon crystal field. Trivalent cobalt is shown to keep the intermediate spin state in the whole temperature range from 10 to 326 K.
TL;DR: In this paper, a spin-polarized-neutron study on multiferroic CuCrO 2 was carried out to clarify the origin of the ferroelectricity.
Abstract: We have carried out a spin-polarized-neutron study on multiferroic CuCrO 2 to clarify the origin of the ferroelectricity. The neutron results demonstrate that an incommensurate proper-screw magnetic structure of CuCrO 2 induces electric polarization. Not only the magnetic structure but also the oxygen location contributes to the ferroelectricity of CuCrO 2 . The electric polarization of CuCrO 2 can be explained not by a conventional spin-current model but by a theoretical prediction proposed by Arima. The spin helicities of CuCrO 2 can be reversed by the reversal of the electric field E in the multiferroic phase.
TL;DR: In this paper, a two-step synthesis of the Nanocrystalline phase pure CeCrO3 was performed by using high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy.
Abstract: Nanocrystalline phase pure CeCrO3 was synthesized by a two-step synthesis. The compound was investigated by a host of characterization techniques such as X-ray diffraction, high-temperature X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric−differential thermal analysis, magnetic and specific heat capacity data, ac impedance spectroscopy, diffuse reflectance DR UV−visible spectrophotometer, and dynamic light scattering. The magnetic structure of CeCrO3 was established using variable-temperature neutron diffraction data. On the basis of the detailed studies, this compound was found to exhibit multifunctionalities such as antiferromagnetism, relaxor behavior, and an optical band gap in the visible region. This newly developed synthesis route opens the immense possibilities of preparation of the hitherto unknown Ce3+-based mixed oxides, analogous to other rare earth (RE3+) counterparts.
TL;DR: The magnetic properties and electronic structure of Mn2NiZ (Z=In, Sn, Sb) have been studied in this article, where the magnetic properties of these alloys are mainly determined by the main-group element Z instead of the distance between the Mn atoms.
TL;DR: The crystal and magnetic structures of the three-leg ladder compound have been investigated by single-crystal x-ray diffraction and neutron powder diffraction as mentioned in this paper, showing a smooth charge ordering and an incomplete charge localization down to 110 K.
Abstract: The crystal and magnetic structures of the three-leg ladder compound ${\text{Fe}}_{3}{\text{BO}}_{5}$ have been investigated by single-crystal x-ray diffraction and neutron powder diffraction. ${\text{Fe}}_{3}{\text{BO}}_{5}$ contains two types of three-leg spin ladders. It shows a charge ordering transition at 283 K, an antiferromagnetic transition at 112 K, ferromagnetism below 70 K, and a weak ferromagnetic behavior below 40 K. The x-ray data reveal a smooth charge ordering and an incomplete charge localization down to 110 K. Below the first magnetic transition, the first type of ladders orders as ferromagnetically coupled antiferromagnetic chains, while below 70 K the second type of ladders orders as antiferromagnetically coupled ferromagnetic chains.
TL;DR: In this paper, the field-induced, antiferromagnetically ordered state in the two-leg spinladder material (Hpip)2CuBr4.
Abstract: Neutron diffraction is used to investigate the field-induced, antiferromagnetically ordered state in the two-leg spin-ladder material (Hpip)2CuBr4. This “classical” phase, a consequence of weak interladder coupling, is nevertheless highly unconventional: its properties are influenced strongly by the spin Luttinger-liquid state of the ladder subunits. We determine directly the order parameter (transverse magnetization), the ordering temperature, the spin structure, and the critical exponents around the transition. We introduce a minimal microscopic model for the interladder coupling and calculate the quantum fluctuation corrections to the mean-field interaction.
TL;DR: The crystal and magnetic structures of the three-leg ladder compound Fe3BO5 have been investigated by single crystal x-ray diffraction and neutron powder diffraction as discussed by the authors, showing a charge ordering transition at 283 K, an antiferromagnetic transition at 112 K, ferromagnetism below 70 K and a weak ferromagnetic behavior below 40K.
Abstract: The crystal and magnetic structures of the three-leg ladder compound Fe3BO5 have been investigated by single crystal x-ray diffraction and neutron powder diffraction. Fe3BO5 contains two types of three-leg spin ladders. It shows a charge ordering transition at 283 K, an antiferromagnetic transition at 112 K, ferromagnetism below 70 K and a weak ferromagnetic behavior below 40K. The x-ray data reveal a smooth charge ordering and an incomplete charge localization down to 110K. Below the first magnetic transition, the first type of ladders orders as ferromagnetically coupled antiferromagnetic chains, while below 70K the second type of ladders orders as antiferromagnetically coupled ferromagnetic chains.
TL;DR: The clinopyroxene compounds LiFeSi 2 O 6 and LiFeGe O 6 have been investigated by constant wavelength neutron diffraction at low temperatures and by bulk magnetic measurements as mentioned in this paper.
TL;DR: In this article, a general method for describing magnetic reconnection in arbitrary three-dimensional magnetic configurations is proposed, based on the field-line mapping technique previously used only for the analysis of a magnetic structure at a given time.
Abstract: A general method for describing magnetic reconnection in arbitrary three-dimensional magnetic configurations is proposed. The method is based on the field-line mapping technique previously used only for the analysis of a magnetic structure at a given time. This technique is extended here so as to analyze the evolution of a magnetic structure. Such a generalization is made with the help of new dimensionless quantities called “slipsquashing factors.” Their large values define the surfaces that border the reconnected or to-be-reconnected magnetic flux tubes for a given period of time during the magnetic evolution. The proposed method is universal, since it assumes only that the time sequence of evolving magnetic field and the tangential boundary flows are known. The application of the method is illustrated for simple examples, one of which was considered previously by Hesse and coworkers in the framework of the general magnetic reconnection theory. The examples help us to compare these two approaches; it reveals also that, just as for magnetic null points, hyperbolic and cusp minimum points of a magnetic field serve as favorable sites for magnetic reconnection. The new method admits a straightforward numerical implementation and provides a powerful tool for the diagnostics of magnetic reconnection in numerical models of solar-flare-like phenomena in space and laboratory plasmas.
TL;DR: The crystal and magnetic structures of the brownmillerite material were investigated using powder X-ray and neutron diffraction methods, the latter from 3.8 to 700 K as discussed by the authors.
TL;DR: A dielectric anomaly has been found near the incommensurate to commensurate antiferromagnetic phase transition (TN2≈230 K) in YBaCuFeO5 ceramics, a compound which crystallizes in an ordered perovskite structure as discussed by the authors.
Abstract: A dielectric anomaly has been found near the incommensurate to commensurate antiferromagnetic phase transition (TN2≈230 K) in YBaCuFeO5 ceramics, a compound which crystallizes in an ordered perovskite structure. The existence of electric polarization below TN2 suggests the magnetism induced charge polarization effect that is also confirmed by its strong magnetic field dependence below TN2. Accordingly, the peak near TN2 of the magnetodielectric effect indicates a maximum of magnetodielectric susceptibility near the spin reorientation transition. Considering the abundance of magnetic compounds which structures derive from the perovskite, these results might open up the way toward the control of electric polarization near room temperature.
TL;DR: In this paper, the electronic and magnetic properties of a layered compound LaMnPO are examined in relation to a newly discovered iso-structural superconductor LaFeAs(P)O.
Abstract: Electronic and magnetic properties of a layered compound LaMnPO are examined in relation to a newly discovered iso-structural superconductor LaFeAs(P)O. Neutron diffraction measurements, together with temperature dependent magnetic susceptibility, clarify that LaMnPO is an antiferromagnet at least up to 375 K. The spin moment of a Mn ion is determined to be 2.26 μB at room temperature, and the spin configuration is antiparallel in the Mn–P plane and parallel between the Mn–P planes, which is rather different from that of LaFeAsO. Optical absorption spectra, photoemission spectra, and temperature dependent electrical conductivity indicate that LaMnPO is a semiconductor. Furthermore, nominally undoped LaMnPO exhibits n-type conduction while the conduction type is changed by doping of Cu or Ca to the La sites, indicating that LaMnPO is a bipolar conductor. Density functional calculation using the GGA+U approximation supports the above conclusions; the electronic band structure has an open band gap and the antiferromagnetic spin configuration is more stable than the ferromagnetic one.