The hydrostatic pressure is expected to be an effective knob to tune the magnetostructural phase transitions of hexagonal MM’X alloys(M and M’denote transition metals and X represents main group elements).We perform...The hydrostatic pressure is expected to be an effective knob to tune the magnetostructural phase transitions of hexagonal MM’X alloys(M and M’denote transition metals and X represents main group elements).We perform magnetization measurements under hydrostatic pressure on an MM’X martensitic MnNi0.77Fe0.23Ge alloy.The magnetostructural transition temperature can be efficiently tuned to lower temperatures by applying moderate pressures,with a giant shift rate of-151 K/GPa.A temperature span of 30 K is obtained under the pressure,within which a large magnetic entropy change of-23 J·kg-1K-1 in a field change of 5 T is induced by the mechanical energy gain due to the large volume change.Meanwhile,a decoupling of structural and magnetic transitions is observed at low temperatures when the martensitic transition temperature is lower than the Curie temperature.These results show a multi-parameter tunable caloric effect that benefits the solid-state cooling.展开更多
本文采用缓慢冷却方法制备了磁性拓扑材料Mn_(1-x)Fe_(x)Al Ge系列单晶样品,并系统研究了Fe掺杂对体系的结构、磁性以及反常霍尔效应的影响.随着Fe含量的增加,体系的晶胞收缩,磁性逐渐降低.在Mn Al Ge中观测到高达~800Ω^(-1)cm^(-1)的...本文采用缓慢冷却方法制备了磁性拓扑材料Mn_(1-x)Fe_(x)Al Ge系列单晶样品,并系统研究了Fe掺杂对体系的结构、磁性以及反常霍尔效应的影响.随着Fe含量的增加,体系的晶胞收缩,磁性逐渐降低.在Mn Al Ge中观测到高达~800Ω^(-1)cm^(-1)的反常霍尔电导率(AHC),并且随着Fe含量增加,体系的AHC逐渐降低.采用对数和TYJ模型对体系AHC的内外禀贡献进行定性和定量分离,其结果显示所有样品中内外禀机制对总的AHC贡献相当,并且两者均随着Fe含量的增加而降低.展开更多
基金Supported by the National Natural Science Foundation of China(Grant No.51722106)the National Key R&D Program of China(Grant No.2019YFA0704904)+1 种基金Users with Excellence Program of Hefei Science Center CAS(Grant No.2019HSC-UE009)Fujian Institute of Innovation,Chinese Academy of Sciences。
文摘The hydrostatic pressure is expected to be an effective knob to tune the magnetostructural phase transitions of hexagonal MM’X alloys(M and M’denote transition metals and X represents main group elements).We perform magnetization measurements under hydrostatic pressure on an MM’X martensitic MnNi0.77Fe0.23Ge alloy.The magnetostructural transition temperature can be efficiently tuned to lower temperatures by applying moderate pressures,with a giant shift rate of-151 K/GPa.A temperature span of 30 K is obtained under the pressure,within which a large magnetic entropy change of-23 J·kg-1K-1 in a field change of 5 T is induced by the mechanical energy gain due to the large volume change.Meanwhile,a decoupling of structural and magnetic transitions is observed at low temperatures when the martensitic transition temperature is lower than the Curie temperature.These results show a multi-parameter tunable caloric effect that benefits the solid-state cooling.
文摘本文采用缓慢冷却方法制备了磁性拓扑材料Mn_(1-x)Fe_(x)Al Ge系列单晶样品,并系统研究了Fe掺杂对体系的结构、磁性以及反常霍尔效应的影响.随着Fe含量的增加,体系的晶胞收缩,磁性逐渐降低.在Mn Al Ge中观测到高达~800Ω^(-1)cm^(-1)的反常霍尔电导率(AHC),并且随着Fe含量增加,体系的AHC逐渐降低.采用对数和TYJ模型对体系AHC的内外禀贡献进行定性和定量分离,其结果显示所有样品中内外禀机制对总的AHC贡献相当,并且两者均随着Fe含量的增加而降低.
