Metamagnetism

About: Metamagnetism is a research topic. Over the lifetime, 2023 publications have been published within this topic receiving 38108 citations.

Influence of negative lattice expansion and metamagnetic transition on magnetic entropy change in the compound LaFe11.4Si1.6

Abstract: Magnetization of the compound LaFe11.4Si1.6 with the cubic NaZn13-type structure was measured as functions of temperature and magnetic field around its Curie temperature TC of ∼208 K. It is found that the magnetic phase transition at TC is completely reversible. Magnetic entropy change ΔS, allowing one to estimate the magnetocaloric effect, was determined based on the thermodynamic Maxwell relation. The achieved magnitude of |ΔS| reaches 19.4 J/kg K under a field of 5 T, which exceeds that of most other materials involving a reversible magnetic transition in the corresponding temperature range. The large entropy change is ascribed to the sharp change of magnetization, which is caused by a large negative lattice expansion at the TC. An asymmetrical broadening of |ΔS| peak with increasing field was observed, which is resulted from the field-induced itinerant-electron metamagnetic transition from the paramagnetic to ferromagnetic state above the TC.

Large magnetocaloric effect in La(FexSi1−x)13 itinerant-electron metamagnetic compounds

Abstract: The magnetocaloric effect (MCE) originated from the itinerant-electron metamagnetic transition for La(FexSi1−x)13 compounds has been investigated. With increasing Fe concentration, the MCE is enhanced and both the isothermal magnetic entropy change ΔSm and the adiabatic temperature change ΔTad for the compound with x=0.90 are −28 J/kg K and 8.1 K, respectively, by changing the magnetic field from 0 to 2 T. Similar large MCE values are achieved around room temperature by controlling the Curie temperature by means of hydrogen absorption. Consequently, La(FexSi1−x)13 compounds are promising as magnetic refrigerant materials working in relatively low magnetic fields.

Metamagnetic shape memory effect in a Heusler-type Ni43Co7Mn39Sn11 polycrystalline alloy

Abstract: Shape memory and magnetic properties of a Ni43Co7Mn39Sn11 Heusler polycrystalline alloy were investigated by differential scanning calorimetry, the sample extraction method, and the three-terminal capacitance method. A unique martensitic transformation from the ferromagnetic parent phase to the antiferromagneticlike martensite phase was detected and magnetic-field-induced “reverse” transition was confirmed in a high magnetic field. In addition, a large magnetic-field-induced shape recovery strain of about 1.0% was observed to accompany reverse martensitic transformation, and the metamagnetic shape memory effect, which was firstly reported in a Ni45Co5Mn36.7In13.3 Heusler single crystal, was confirmed in a polycrystalline specimen.

Electric polarization rotation in a hexaferrite with long-wavelength magnetic structures.

Abstract: We report on the control of electric polarization (P) by using magnetic fields (B) in a hexaferrite having magnetic order above room temperature (RT). The material investigated is hexagonal Ba0.5Sr1.5Zn2Fe12O22, which is a nonferroelectric helimagnetic insulator in the zero-field ground state. By applying B, the system undergoes successive metamagnetic transitions, and shows concomitant ferroelectric order in some of the B-induced phases with long-wavelength magnetic structures. The magnetoelectrically induced P can be rotated 360 degrees by external B. This opens up the potential for not only RT magnetoelectric devices but also devices based on the magnetically controlled electro-optical response.

Magnetic Properties of Transition Metal Compounds

Abstract: I. Paramagnetism: The Curie Law.- A. Introduction.- B. Diamagnetism and Paramagnetism.- C. Magnetic Moment of a Magnetic Ion Subsystem.- D. Some Curie Law Magnets.- E. Susceptibilities of the Lanthanides.- F. Temperature Independent Paramagnetism.- References.- II. Thermodynamics and Relaxation.- A. Introduction.- B. Thermodynamic Relations.- C. Thermal Effects.- D. Adiabatic Demagnetization.- E. Relaxation Time and Transition Probability.- F. Spin-lattice Relaxation Processes.- G. Susceptibility in Alternating Fields.- H. Adiabatic Susceptibilities.- References.- III. Paramagnetism: Zero-Field Splittings.- A. Introduction.- B. Schottky Anomalies.- C. Adiabatic Demagnetization.- D. Van Vleck's Equation.- E. Paramagnetic Anisotropy.- F. Effective Spin.- G. Direct Measurement of D.- H. Electron Paramagnetic Resonance (EPR).- References.- IV. Dimers and Clusters.- A. Introduction.- B. Energy Levels and Specific Heats.- C. Magnetic Susceptibilities.- D. Copper Acetate and Related Compounds.- E. Some Other Dimers.- F. EPR Measurements.- G. Clusters.- H. The Ising Model.- References.- V. Long-Range Order.- A. Introduction.- B. Molecular Field Theory of Ferromagnetism.- C. Thermal Effects.- D. Molecular Field Theory of Antiferromagnetism.- E. Ising, XY, and Heisenberg Models.- F. Critical Point Exponents.- G. Cu(NO3)2*21/2H2O.- H. Dipole-Dipole Interactions.- I. Exchange Effects on Paramagnetic Susceptibilities.- J. Superexchange.- References.- VI. Short-Range Order.- A. Introduction.- B. One-Dimensional or Linear Chain Systems.- C. Two-Dimensional or Planar Systems.- D. Long-Range Order.- References.- VII. Special Topics: Spin-Flop, Metamagnetism, Ferrimagnetism and Canting.- A. Introduction.- B. Phase Diagrams and Spin-Flop.- C. Metamagnetism.- D. Ferrimagnetism.- E. Canting and Weak Ferromagnetism.- References.- VIII. Selected Examples.- A. Introduction.- B. Some Single Ion Properties.- 1. Ti3+.- 2. V3+.- 3. VO2+.- 4. Cr3+.- 5. Mn2+.- 6. Fe3+.- 7. Fe2+ and Cr2+.- 8. Co2+.- 9. Ni2+.- 10. Cu2+.- 11. Lanthanides.- C. Some Examples.- 1. Iron(III) Methylammonium Sulfate.- 2. CaCu(OAc)4*6H2O.- 3. Hydrated Nickel Halides.- 4. Hydrated Nickel Nitrates.- 5. Tris Dithiocarbamates of Iron(III).- 6. Spin-3/2 Iron(III).- 7. Manganous Acetate Tetrahydrate.- 8. [M(C5H5NO)6]ClO4)2.- 9. NiX2L2.- 10. [(CH3)3NH]MX3*2H2O.- References.- Append.- A. Physical Constants.- B. Hyperbolic Functions.- Formula Index.