论文信息 - Magnetic order and phase transformation in Ni2MnGa

Magnetic order and phase transformation in Ni2MnGa

Abstract Magnetization, magnetic susceptibility, optical microscopy, X-ray diffraction and neutron diffraction measurements have been made on a quenched sample of Ni2MnGa. Room-temperature neutron diffraction patterns indicate a highly ordered Heusler alloy, L21 type, structure. The alloy is ferromagnetic with a Curie temperature of 376 K, and a magnetic moment of 4·17μB largely confined to the Mn sites, but probably with a small moment <07·3μB associated with the Ni sites. A martensitic phase transition to a complex tetragonal structure occurs on cooling below 202 K. Neutron diffraction oscillation photographs taken using the D12 facility at Institut Laue Langevin, Grenoble, and low-temperature powder neutron diffraction data enabled details of the low temperature crystallographic superlattice and magnetic structure to be determined. Reasons for the structural transformation are discussed.

P. J. Webster | K. Ziebeck | K. R. A. Ziebeck | S. L. Town | M. S. Peak

[1] P. J. Webster,et al. Magnetic order in palladium-based heusler alloys: Part 2: Pd2MnIn1−ySby , 1979 .

[2] J. Smit. Magnetism in Hume-Rothery alloys , 1978 .

[3] P. J. Webster,et al. Magnetic order in palladium-based Heusler alloys Part I: Pd2MnIn1−xSnx and Pd2MnSn1−xSbx , 1977 .

[4] P. J. Webster,et al. Helical magnetic order in Ni2MnAl , 1975 .

[5] J. Crangle,et al. The magnetization of pure iron and nickel , 1971, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[6] P. J. Webster,et al. Magnetic and Chemical Order in Pd2MnAl in Relation to Order in the Heusler Alloys Pd2MnIn, Pd2MnSn, and Pd2MnSb , 1968 .

[7] P. J. Webster,et al. The magnetic and chemical ordering of the heusler alloys Pd2MnIn, Pd2MnSn and Pd2MnSb , 1967 .

[8] R. S. Toth,et al. Effect of Additional Elements on the Period of CuAu II and the Origin of the Long-Period Superlattice , 1961 .

[9] R. E. Watson,et al. Hartree–Fock atomic scattering factors for the iron transition series , 1961 .

[10] F. Hames. Ferromagnetic-Alloy Phases Near the Compositions Ni2MnIn, Ni2MnGa, Co2MnGa, Pd2MnSb, and PdMnSb , 1960 .

[11] H. Jones. Applications of the Bloch Theory to the Study of Alloys and of the Properties of Bismuth , 1934 .