Kazakov Alexander, Prudnikov Valerii, Granovsky Alexander, Perov Nikolai, Dubenko Igor, Pathak Arjun Kumar, Samanta Tapas, Stadler Shane, Ali Naushad, Zhukov Arcady, Ilyin Maxim, Gonzalez Julian
Faculty of Physics, Moscow State University, Vorob'evy Gory, 119991 Moscow, Russia.
J Nanosci Nanotechnol. 2012 Sep;12(9):7426-31. doi: 10.1166/jnn.2012.6542.
The magnetic, magnetotransport, and magnetocaloric properties near compound phase transitions in Ni50Mn35In14Z (Z = In, Ge, Al), and Ni48Co2Mn35In15 Heusler alloys have been studied using VSM and SQUID magnetometers (at magnetic fields (H) up to 5 T), four-probe method (at H = 0.005-1.5 T), and an adiabatic magnetocalorimeter (for H changes up to deltaH = 1.8 T), respectively. The martensitic transformation (MT) is accompanied by large magnetoresistance (up to 70%), a significant change in resistivity (up to 200%), and a sign reversal of the ordinary Hall effect coefficient, all related to a strong change in the electronic spectrum at the MT. The field dependences of the Hall resistance are complex in the vicinity of the MT, indicating a change in the relative concentrations of the austenite and martensite phases at strong fields. Negative and positive changes in adiabatic temperatures of about -2 K and +2 K have been observed in the vicinity of MT and Curie temperatures, respectively, for deltaH = 1.8 T.
已分别使用振动样品磁强计（VSM）和超导量子干涉仪磁强计（在高达5 T的磁场（H）下）、四探针法（在H = 0.005 - 1.5 T下）以及绝热熔量计（对于高达ΔH = 1.8 T的H变化）研究了Ni50Mn35In14Z（Z = In、Ge、Al）和Ni48Co2Mn35In15 Heusler合金在复合相变附近的磁性、磁输运和磁热性质。马氏体相变（MT）伴随着大磁阻（高达70%）、电阻率的显著变化（高达200%）以及普通霍尔效应系数的符号反转，所有这些都与MT处电子能谱的强烈变化有关。在MT附近，霍尔电阻的场依赖性很复杂，这表明在强磁场下奥氏体和马氏体相的相对浓度发生了变化。对于ΔH = 1.8 T，分别在MT和居里温度附近观察到了约 -2 K和 +2 K的绝热温度的负向和正向变化。
