Showing papers on "Metamagnetism published in 2010"
TL;DR: In this paper, a tripodal carboxylic ligand, 5-(4-carboxy-phenoxy)-isophthalic acid, readily reacts with Co(II) salts in the presence of pyridine-based coligands under solvothermal conditions to afford four different coordination polymers.
Abstract: A new tripodal carboxylic ligand, 5-(4-carboxy-phenoxy)-isophthalic acid, readily (cpiaH3) reacts with Co(II) salts in the presence of pyridine-based coligands under solvothermal conditions to afford four different coordination polymers, {Co2(cpia)(OH)(bipy)0.5}n (1), {[Co2(cpia)(OH)(H2O)2]·H2O}n (2), {Co1.5(cpia)(bipyethane)}n (3), and {Co1.5(cpia)(pyridine)2}n (4). All these coordination polymers have been characterized by single crystal X-ray diffraction, IR spectroscopy, thermogravimetry and elemental analysis. The structures of 1 and 2 can be described as a repetition of a tetranuclear core with subtle differences — two tetranuclear cores are shared by an O atom in 2, while no such bridging is present in 1. The structures of 3 and 4, on the other hand, consist of a trinuclear core extending to three-dimensional networks. Variable temperature magnetic susceptibility measurements indicate that 1 exhibits ferromagnetic behavior below 13 K, while 2 shows metamagnetic behavior. These interesting magnetic ...
128 citations
TL;DR: In this article, the magnetic properties and magnetocaloric effect of antiferromagnetic HoCuSi compound have been studied, and it was found that HoCSi undergoes a field-induced first order metamagnetic transition from antiferrous (AFM) to ferromagnetic (FM) states below the Neel temperature (TN).
Abstract: The magnetic properties and magnetocaloric effect (MCE) of antiferromagnetic HoCuSi compound have been studied. It is found that HoCuSi undergoes a field-induced first order metamagnetic transition from antiferromagnetic (AFM) to ferromagnetic (FM) states below the Neel temperature (TN). A giant MCE without hysteresis loss is observed in HoCuSi around TN. The maximal magnetic entropy change (−ΔSM) and refrigerant capacity are 33.1 J/kgK and 385 J/kg, respectively, for a field change of 0–5 T. The excellent magnetocaloric properties can result from the field-induced AFM-FM transition below TN and the increase in magnetization change caused by the change in lattice volume at TN.
112 citations
TL;DR: In this paper, the magnetic and dielectric properties of single-domain BiFeO 3 were studied in pulsed magnetic fields up to 55 T. At low temperatures, metamagnetic transitions accompanied with sharp changes in electric polarization (P ) were observed at around 18 T. The angular dependence of the transition field coincides with that of the cycloidal state to the canted antiferromagnetic spin state studied in the framework of the Landau-Ginzburg theory incorporated with the Lifshitzlike invariant.
Abstract: Magnetic and dielectric properties of single-domain crystals of BiFeO 3 were studied in pulsed magnetic fields up to 55 T. At low temperatures, metamagnetic transitions accompanied with sharp changes in electric polarization ( P ) were observed at around 18 T. The angular dependence of the transition field coincides with that of the transition from the cycloidal state to the canted antiferromagnetic spin state studied in the framework of the Landau–Ginzburg theory incorporated with the Lifshitz-like invariant. The parasitic P component caused by the cycloidal spin structure amounts to 210±30 µC/m 2 in terms of the projected component on the pseudocubic principal axis, which can be controlled by applying magnetic fields at least up to 500 K. This result indicates that the microscopic magnetoelectric coupling in BiFeO 3 is not weak: In fact, it is rather strong as compared to that in the canonical multiferroic material TbMnO 3 .
76 citations
TL;DR: In this article, the magnetic and magnetocaloric properties of HoMnO3 single crystal were investigated, and it was shown that the phase transitions due to the long range ordering of Mn3+ and Ho3+ moments produced a metamagnetic transition.
Abstract: We have investigated the magnetic and magnetocaloric properties of HoMnO3 single crystal. HoMnO3 displays a series of complicated phase transitions due to the long range ordering of Mn3+ and Ho3+ moments. Field variation in magnetization generates a metamagnetic transition and produces an entropy change of 13.1 J/kg K at 7 T in the vicinity of antiferromagnetic ordering temperature of Ho3+. The values of adiabatic temperature change (∼6.5 K) and relative cooling power (∼320 J/kg) for a field change of 7 T are also appreciable to consider HoMnO3 as a magnetic refrigerant at low temperature.
73 citations
TL;DR: In this paper, magnetic and magnetocaloric properties of Pr0.68Ca0.32−xSrxMnO3 (x=0, 0.18,0.26 and 0.32) compounds were investigated and X-ray results indicated that all the samples have a single phase of orthorhombic symmetry.
71 citations
TL;DR: In this paper, it was shown that 3+1 dimensional gauge theories holographically dual to 4 + 1 dimensional Einstein-Maxwell-Chern-Simons theory undergo a quantum phase transition in the presence of a finite charge density and magnetic field.
Abstract: Using high-precision numerical analysis, we show that 3+1 dimensional gauge theories holographically dual to 4 + 1 dimensional Einstein-Maxwell-Chern-Simons theory undergo a quantum phase transition in the presence of a finite charge density and magnetic field. The quantum critical theory has dynamical scaling exponent z = 3, and is reached by tuning a relevant operator of scaling dimension 2. For magnetic field B above the critical value B
c
, the system behaves as a Fermi liquid. As the magnetic field approaches B
c
from the high field side, the specific heat coefficient diverges as 1/(B - B
c
), and non-Fermi liquid behavior sets in. For B < B
c
the entropy density s becomes non-vanishing at zero temperature, and scales according to $$ s \sim \sqrt {{B_c} - B} $$
. At B = B
c
, and for small non-zero temperature T, a new scaling law sets in for which s ∼ T
1/3. Throughout a small region surrounding the quantum critical point, the ratio s/T
1/3 is given by a universal scaling function which depends only on the ratio (B - B
c
)/T
2/3. The quantum phase transition involves non-analytic behavior of the specific heat and magnetization but no change of symmetry. Above the critical field, our numerical results are consistent with those predicted by the Hertz/Millis theory applied to metamagnetic quantum phase transitions, which also describe non-analytic changes in magnetization without change of symmetry. Such transitions have been the subject of much experimental investigation recently, especially in the compound Sr3Ru2O7, and we comment on the connections.
70 citations
TL;DR: In this paper, it was shown that 3+1 dimensional gauge theories can undergo a quantum phase transition in the presence of a finite charge density and magnetic field, and that the quantum critical theory has dynamical scaling exponent z = 3, and is reached by tuning a relevant operator of scaling dimension 2.
Abstract: Using high-precision numerical analysis, we show that 3+1 dimensional gauge theories holographically dual to 4+1 dimensional Einstein-Maxwell-Chern-Simons theory undergo a quantum phase transition in the presence of a finite charge density and magnetic field. The quantum critical theory has dynamical scaling exponent z=3, and is reached by tuning a relevant operator of scaling dimension 2. For magnetic field B above the critical value B_c, the system behaves as a Fermi liquid. As the magnetic field approaches B_c from the high field side, the specific heat coefficient diverges as 1/(B-B_c), and non-Fermi liquid behavior sets in. For B
65 citations
TL;DR: In this paper, an irreversible character of ΔTad has been observed in the vicinity of the reverse martensitic transformation in a Ni50Mn36Co1Sn13 metamagnetic shape memory alloy.
Abstract: We have studied adiabatic temperature change ΔTad in a Ni50Mn36Co1Sn13 metamagnetic shape memory alloy. An irreversible character of ΔTad has been observed in the vicinity of the reverse martensitic transformation. In this region, cyclic application of the magnetic field converts comparatively large inverse magnetocaloric effect (MCE) with ΔTadmax=−0.8 K to a weaker conventional MCE (ΔTadmax=0.3 K). The crossover of ΔTad has been attributed to the irreversible character of the magnetic field-induced transformation and the closeness of the martensitic transformation and Curie temperature of the austenitic phase TCA.
64 citations
TL;DR: In this paper, the structural conditions for metamagnetism in MnP and related materials using density-functional theory were investigated and a magnetic stability plot was constructed taking into account the two shortest Mn-Mn distances.
Abstract: We investigate the structural conditions for metamagnetism in MnP and related materials using density-functional theory. A magnetic stability plot is constructed taking into account the two shortest Mn-Mn distances. We find that a particular Mn-Mn separation plays the dominant role in determining the change from antiferromagnetic to ferromagnetic order in such systems. We establish a good correlation between our calculations and structural and magnetic data from the literature. Based on our approach it should be possible to find Mn-containing alloys that possess field-induced metamagnetism and associated magnetocaloric effects.
62 citations
TL;DR: In this paper, it was shown that in metamagnetic shape memory alloys exhibiting a magnetostructural first order phase transition the direct transition from ferromagnetic austenite to nonmagnetic martensite is isothermal.
Abstract: We show that in metamagnetic shape memory alloys exhibiting a magnetostructural first order phase transition the direct transition from ferromagnetic austenite to nonmagnetic martensite is isothermal. In contrast to the direct transformation, the reverse one (nonmagnetic martensite–ferromagnetic austenite) is athermal, just as are athermal both direct and reverse martensitic transformations in conventional ferromagnetic shape memory alloys. The observed asymmetry of properties of the direct and reverse phase transitions in metamagnetic alloys, together with the data on entropy change during the magnetostructural transition, evidences that the magnetostructural transition is driven by the first order lattice modification. The change in magnetic ordering is an effect accompanying the lattice modification, opposing the direct transformation and promoting the reverse one. It has been shown that relaxation effects in metamagnetic shape memory alloys are intrinsic in the direct transformation itself and do not require the “arrest” of the transformation.
50 citations
TL;DR: In this paper, the metamagnetic behavior in the heavy-fermion compound YbIr 2 Zn 20 with a cubic structure was studied by magnetization, de Haas-van Alphen oscillation, magnetoresistance, specific heat, thermal expansion, and magnetostriction measurements in single-crystalline samples.
Abstract: The metamagnetic behavior in the heavy-fermion compound YbIr 2 Zn 20 with a cubic structure was studied by magnetization, de Haas–van Alphen (dHvA) oscillation, magnetoresistance, specific heat, thermal expansion, and magnetostriction measurements in single-crystalline samples. A metamagnetic anomaly at H m ≃100 kOe was found to exist in all field directions in the cubic crystal structure. The cyclotron effective mass m c * , the coefficient A in the Fermi liquid relation of electrical resistivity ρ=ρ 0 + A T 2 , and the electronic specific heat coefficient C / T indicate a peak at the metamagnetic field H m . The negative thermal expansion and negative volume magnetostriction suggest that the valence of the Yb ion gradually changes from a 4 f -itinerant state to a trivalent state with increasing magnetic field, and an almost trivalent state is realized above the metamagnetic field H m . On the other hand, the topology of the Fermi surface is approximately unchanged below and above H m in the dHvA experiment.
TL;DR: In this paper, magnetic properties and magnetocaloric effects of Dy3Co compounds are studied. And the maximal value of magnetic entropy changeS m is −13.9 J/kg K with a refrigerant capacity (RC) of 498 J/ kg around the Neel temperature.
Abstract: Magnetic properties and magnetocaloric effects (MCEs) of the Dy3Co compound are studied. Two succes- sive magnetic transitions: the antiferromagnetic (AFM)-to- AFM transition at TAF = 29 K and the AFM-to-paramag- netic (PM) transition with increasing temperature at the Neel temperature TN = 44 K are observed. Dy3Co undergoes a field-induced metamagnetic transition from the AFM to the ferromagnetic (FM) state below TN ,g iving rise to al arge MCE. The maximal value of magnetic entropy changeS m is −13.9 J/kg K with a refrigerant capacity (RC) of 498 J/kg around TN for a field change of 0-5 T. A sign change of MCE in Dy3Co with magnetic field and temperature is ob- served near the critical field where the metamagnetic transi- tion occurs.
TL;DR: In this article, the magnetic properties and magnetocaloric effects of intermetallic DyCuSi compound have been investigated by means of magnetization measurements and the maximal magnetic entropy change ( − Δ S M ) and refrigerant capacity (RC) are 24.0 and 381 J/kg, respectively, for the field change of 0−5 T.
Abstract: Magnetic properties and magnetocaloric effects (MCEs) have been investigated in hydrogenated La0.5Pr0.5Fe11.4Si1.6Hx (x=0, 0.9, and 1.6) compounds. It is found that the Curie temperature TC can be tuned from 189 to 317 K by adjusting hydrogen content from 0 to 1.6. It is attractive that both thermal and magnetic hysteresis are remarkably reduced because of the weakness of the itinerant-electron metamagnetic transition after hydrogenation, while the large magnetic entropy change is retained. The maximal hysteresis loss at TC decreases from 17.8 to 2.3 J/kg as x increases from 0 to 1.6. For the samples with x=0, 0.9, and 1.6, the maximal values of −ΔS are 26.3, 24.1, and 22.1 J/kg K at TC, with efficient refrigeration capacities of 463, 366, and 351 J/kg for a field change of 0–5 T, respectively. Large reversible MCE and small hysteresis with considerable value of refrigeration capacity indicate the potentiality of La0.5Pr0.5Fe11.4Si1.6Hx hydrides as a candidate magnetic refrigerant around room temperature.
TL;DR: In this article, a metamagnetic anomaly at H m ≃5 kOe in a heavy fermion compound YbCo 2 Zn 20 below the characteristic temperature T χ max = 0.32 K where the ac-susceptibility shows a broad peak, suggesting that an electronic state with a very low Kondo temperature is realized.
Abstract: We found a metamagnetic like anomaly at H m ≃5 kOe in a heavy fermion compound YbCo 2 Zn 20 below the characteristic temperature T χ max =0.32 K where the ac-susceptibility shows a broad peak, suggesting that an electronic state with a very low Kondo temperature is realized. Interestingly, the metamagnetic like behavior was observed as two peaks at 4.0 and 7.5 kOe at 95 mK in the magnetic field dependence of the electronic specific heat C / T . The extremely large values of the electronic specific heat coefficient γ≃8000 mJ/(K 2 ·mol) and A =160 µΩ·cm/K 2 in the electrical resistivity ρ=ρ 0 + A T 2 at H =0 kOe are most likely due to the very low Kondo temperature. The \(\sqrt{A}\) value was, however, found to be strongly reduced from \(\sqrt{A}=12.6\) (µΩ·cm/K 2 ) 1/2 at 0 kOe to 0.145 (µΩ·cm/K 2 ) 1/2 at 150 kOe. Therefore, we considered that the corresponding cyclotron effective mass m c * , which was determined from the temperature dependence of the de Haas–van Alphen (dHvA) amplitude, is also reduced ...
TL;DR: A family of rare-earth cobalt phosphides La1−xPrxCo2P2 (0 ≤ x ≤ 1) that belong to the ThCr2Si2 structure type has been prepared and characterized by structural and magnetic methods and electronic band structure calculations as discussed by the authors.
Abstract: A family of rare-earth cobalt phosphides La1−xPrxCo2P2 (0 ≤ x ≤ 1) that belong to the ThCr2Si2 structure type has been prepared and characterized by structural and magnetic methods and electronic band structure calculations. All studied quaternary phases exhibit multiple magnetic transitions, leading to an observation of ferro- and metamagnetism and magnetic pole reversal. The ferromagnetic transition temperature of LaCo2P2 (132 K) increases dramatically upon substitution of Pr for La and reaches 268 K for La0.25Pr0.75Co2P2. This increase is accompanied by elongation of intralayer Co−Co distances. Variable temperature X-ray diffraction data revealed that temperature dependences of unit cell parameters, and, correspondingly, both intra- and interlayer Co−Co separations show anomalous changes at temperatures close to the ferromagnetic transition. The electronic structure calculations reveal a strong peak in the nonmagnetic density of states (DOS). This instability is removed in the spin-polarized DOS due to...
TL;DR: In this article, the magnetic field effect on the spin gap state in CeRu 2 Al 10 was investigated by measuring the magnetization and electrical resistivity. And the obtained magnetic phase diagram strongly indicated the existence of a fine structure on a low-energy side with an excitation energy of 8 meV, which has been observed in inelastic neutron scattering experiments.
Abstract: We investigate the magnetic field effect on the spin gap state in CeRu 2 Al 10 by measuring the magnetization and electrical resistivity. We found that the magnetization curve for the magnetic field H ∥ c shows a metamagnetic-like anomaly at H * ∼4 T below T 0 =27 K, but no anomaly for H ∥ a or H ∥ b . A shoulder of the electrical resistivity at T s ∼5 K for I ∥ c is suppressed by applying a longitudinal magnetic field above 5 T. Many anomalies are also found in the magnetoresistance for H ∥ c below ∼5 K. The obtained magnetic phase diagram consists of at least two or three phases below T 0 . These results strongly indicate the existence of a fine structure on a low-energy side in a spin gap state with an excitation energy of 8 meV, which has recently been observed in inelastic neutron scattering experiments.
TL;DR: Er4NiCd as mentioned in this paper shows Curie-Weiss behavior above 50 K with T-N=5.9 K and the corresponding RCP of 595 J kg(-1) is relatively high as compared to other MCE materials in that temperature range.
Abstract: Er4NiCd crystallizes with the Gd4RhIn type structure, space group F (4) over bar 3m, a=1333.3 pm. The nickel atoms have trigonal prismatic rare earth coordination. Condensation of the NiEr6 prisms leads to a three-dimensional network which leaves voids that are filled by regular Cd-4 tetrahedra. Er4NiCd shows Curie-Weiss behavior above 50 K with T-N=5.9 K. At field strength of 4 kOe a metamagnetic step is visible, together with the positive paramagnetic Curie-temperature (7.5 K) indicative for the rather unstable antiferromagnetic ground state. Therefore, a large reversible magnetocaloric effect (MCE) near the ordering temperature occurs and the values of the maximum magnetic-entropy change -Delta S-M(max) reach 18.3 J kg(-1) K-1 for the field change of 5 T with no obvious hysteresis loss around 17 K. The corresponding RCP of 595 J kg(-1) is relatively high as compared to other MCE materials in that temperature range. These results indicate that Er4NiCd could be a promising system for magnetic refrigeration at temperatures below liquid H-2. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3518556] (Less)
TL;DR: The magnetic properties of 10 nm size Ni(OH)2 nanoparticles prepared by sol-gel method have been studied in this paper, where the magnetic moments increase with decreasing temperature in a low applied field, which is due to the spin-frozen-like state at low temperatures, and the metamagnetic transition is not clearly observed even in an applied field of 70 kOe due to size effect.
Abstract: The magnetic properties of 10 nm size Ni(OH)2 nanoparticles prepared by sol-gel method have been studied. The magnetic moments increase with decreasing temperature in a low applied field, which is due to the spin-frozen-like state at low temperatures, and the metamagnetic transition is not clearly observed even in an applied field of 70 kOe due to the size effect. Furthermore, the transition from paramagnetic to antiferromagnetic in the Ni(OH)2 nanoparticles occurs at lower temperature (22 K).
TL;DR: In this article, the properties of R NiGe 3 (R =Y, Ce-Nd, Sm, Gd-Lu) single crystals were studied by measuring crystal structure and stoichiometry, magnetic susceptibility, magnetization, electrical resistivity, magnetoresistance and specific heat.
TL;DR: In this paper, the magnetocaloric effect in La5/8−yPryCa3/8MnO3 (y=0.3) and Pr0.5Ca0.09Sr0.41MnNO3 manganites was studied.
Abstract: We present a study of the magnetocaloric effect in La5/8−yPryCa3/8MnO3 (y=0.3) and Pr0.5Ca0.09Sr0.41MnO3 manganites. The low temperature state of both systems is the result of a competition between the antiferromagnetic and ferromagnetic phases. The samples display magnetocaloric effect evidenced in an adiabatic temperature change during a metamagnetic transition from an antiferromagnetic to a ferromagnetic phase. As additional features, La5/8−yPryCa3/8MnO3 exhibits phase separation characterized by the coexistence of antiferromagnetic and ferromagnetic phases and Pr0.5Ca0.09Sr0.41MnO3 displays inverse magnetocaloric effect in which temperature decreases while applying an external magnetic field. In both cases, a significant part of the magnetocaloric effect appears from nonreversible processes. As the traditional thermodynamic description of the effect usually deals with reversible transitions, we developed an alternative way to calculate the adiabatic temperature change in terms of the change of the rel...
TL;DR: In this paper, the authors present thermodynamic and neutron scattering data on silver ferrite AgFeO(2) and show that strong magnetic frustration Θ/T(N)∼10 and magnetic ordering arise via two successive phase transitions at T (2) = 7 K and T(1) = 16 K.
Abstract: We present thermodynamic and neutron scattering data on silver ferrite AgFeO(2). The data imply that strong magnetic frustration Θ/T(N)∼10 and magnetic ordering arise via two successive phase transitions at T(2) = 7 K and T(1) = 16 K. At T
TL;DR: In this article, single crystals of hydrides of the intermetallic compound Lu 2 Fe 16.5 Ru 0.5 H 0.6 under hydrostatic pressures up to 0.9 GPa.
TL;DR: In this paper, the electrical resistivity under pressure and magnetic field for a heavy fermion compound YbIr 2 Zn 20 with a cubic cage structure was measured, and it was shown that the residual resistivity is enhanced at 5.0 GPa under 0 kOe.
Abstract: We measured the electrical resistivity under pressure and magnetic field for a heavy fermion compound YbIr 2 Zn 20 with a cubic cage structure. Metamagnetic transition, which is characteristic in the heavy fermion compounds, occurs at the magnetic field H m = 97 kOe for H ∥ at ambient pressure, shifts to lower magnetic fields with increasing pressure P , and becomes zero at the critical pressure P c ≃5.2 GPa. From this experiment, we noted that the metamagnetic transition field H m is a good tuning parameter to approach the quantum critical point. Correspondingly, the A value of the electrical resistivity ρ= ρ 0 + A T 2 in the Fermi liquid relation under magnetic field indicates a peak structure at H m and increases extremely in magnitude from A = 0.29 µΩ·cm/K 2 at ambient pressure to 380 µΩ·cm/K 2 at 5.0 GPa under 0 kOe. The present large A value at 5.0 GPa is, however, strongly reduced in magnetic field: 1.45 µΩ·cm/K 2 at 80 kOe. It is also noted that the residual resistivity is enhanced at 5.0 and...
TL;DR: In this article, the authors study the calorimetric and magnetic behavior of melt-spun LaFe11.6Si1.4, a potential magnetic refrigerant material system that exhibits the rare combination of a large entropy change and low thermal and magnetic field hysteresis.
Abstract: Here we study the calorimetric and magnetic behaviour of melt-spun LaFe11.6Si1.4, a potential magnetic refrigerant material system that exhibits the rare combination of a large entropy change and low thermal and magnetic field hysteresis. We are able to separate the calorimetric contribution from latent heat and changes in equilibrium heat capacity explicitly by using two separate calorimetric probes. The heat capacity of this sample exhibits significant changes of the order of 500?1000?J?K?1?kg?1 in response to magnetic field that results in large changes in entropy. The different contributions to entropy change from latent heat and heat capacity are shown to evolve as the material is field driven through its itinerant metamagnetic transition. We demonstrate explicitly that in the melt-spun sample studied here, the majority of the total entropy change comes from the equilibrium change of heat capacity.
TL;DR: In this paper, the 1D spin-1/2 Ising model with the Dzyaloshinskii-Moriya (DM) interaction is considered and a numerical analysis of the low-energy excitation spectrum and the ground-state magnetic phase diagram of the system using Lanczos method is presented.
Abstract: The 1D spin-1/2 Ising model with the Dzyaloshinskii–Moriya (DM) interaction is considered. A numerical analysis of the low-energy excitation spectrum and the ground-state magnetic phase diagram of the system using Lanczos method is presented. The DM interaction-dependency is calculated for the low-energy excitation spectrum, spiral-order parameter and spin–spin correlation functions. It is showed that the properties of the ferromagnetic and antiferromagnetic Ising chains are very different in presence of DM interaction. In particular a metamagnetic quantum phase transition occurs in the case of a ferromagnetic chain between the ferromagnetic and spiral phases. The existence of the metamagnetic phase transition is confirmed, using the variational matrix product states approach.
TL;DR: In this article, the magnetoelectrical properties of polycrystalline Pr0.58Ca0.42MnO3 thin films (thickness∼300nm) deposited on single crystal LaAlO3 (LAO) and SrTiO3(STO) substrates are reported.
Abstract: We report the magnetoelectrical properties of polycrystalline Pr0.58Ca0.42MnO3 thin films (thickness∼300 nm) deposited on single crystal LaAlO3 (LAO) and SrTiO3 (STO) substrates. The films on LAO show charge ordering (CO) at TCO≈240 K, with a metamagnetic ground state akin to the cluster glass (CG). In PCMO/STO films the CO is quenched and enhanced magnetic moment in the CG state suggests stronger ferromagnetic component. The resistivity of the films on LAO and STO differ drastically, the former has temperature dependence typical to the CO state, while the later show thermal cycling dependent insulator-metal transition (IMT). The large hysteresis in the temperature dependent resistivity provides the evidence of cluster coexistence. The films on STO also exhibit colossal magnetoresistance (CMR∼91%) at moderate magnetic field (∼10 kOe). The CO quenching, IMT, and CMR are explained in terms of the substrate induced magnetoelectrical phase coexistence.
TL;DR: In this article, the effects of substitutions of Ru for Fe and Ce for Lu on magnetic and thermal properties of Lu 2 Fe 17 are studied by means of magnetization and specific heat measurements.
TL;DR: Magnetoresistance and magnetocaloric effect around martensitic transformation were investigated in a Ni45Co5Mn36.5 alloy as discussed by the authors, where the maximum MR exceeds 80% under a field of 5 T around 235 K.
Abstract: Magnetoresistance (MR) and magnetocaloric effect around martensitic transformation were investigated in a Ni45Co5Mn36.5In13.5 alloy. The martensitic temperature (TM) locates at ∼260 K. An external magnetic field can drive TM to a lower temperature at a rate of ∼9.2 K/T. Associated with the field-induced metamagnetic behaviors, a large MR takes place. The maximal MR exceeds 80% under a field of 5 T around 235 K. More attractive is that the MR behavior is fully recoverable against magnetic field. We also studied the magnetocaloric effect associated with the martensitic transformation and found a large magnetic entropy change (ΔS) around 252 K.
TL;DR: In this paper, a detailed study of strain behavior associated with martensitic transition in polycrystalline Ni45Co5Mn37In13 Heusler alloy is presented.
Abstract: We present a detailed study of strain behavior associated with martensitic transition in polycrystalline Ni45Co5Mn37In13 Heusler alloy. A spontaneous phase transition strain with the value of about 0.4% in this alloy can be acquired by applying and removing magnetic field, exhibiting a large two-way metamagnetic shape memory effect (MSME) with nonprestrain. This effect is originated from magnetoelastic coupling due to a large difference in Zeeman energy between austenitic and martensitic phases. In addition, it was also found that even after three magnetic field cycles at 320 K, the two-way MSME is still reproducible. Such characteristic could be ascribed to a random orientation of martensite variants in present alloy.