The effect of hydrostatic pressure on resistivity and magnetic ac susceptibility has been studied in Mn-doped CdGeAs2 room-temperature (RT) ferromagnetic chalcopyrite with two types of MnAs micro-clusters. The slight increase of temperature by about 30 K in the region between RT and Curie temperature TC causes a significant change in the positions of pressure-induced semiconductor-metal transition and magnetic phase transitions in low pressure area. By conducting measurements of the anomalous Hall resistance in the field H \leq 5 kOe, we present experimental evidence for pressure-induced metamagnetic-like state during the paramagnetic phase at pressure P = 5 GPa.
Glassy magnetic behavior in the metamagnetic DyAlO3 doped with Cr
研究了DyAl $_{0.926}$ Cr $_{0.074}$ O $_3$和DyAl O $_3$的磁性。我们发现这两种化合物都是反铁磁的,具有较低的Néel转变温度。在较高的温度下,磁特性表现出居里-外斯依赖性。当外加约2 T的磁场时,Néel温度消失,系统由反铁磁转变为弱铁磁。此外,在不同频率下,Cr掺杂化合物中的AC磁性测量显示出类似自旋玻璃的行为。这些转变进行了研究,并证实了比热测量。我们发现在掺杂有铬的化合物中存在变磁性和自旋玻璃,确定少量铬原子的添加改变了化合物DyAlO $_3$的磁性,从而导致诸如自旋玻璃样行为的新特征。
Ferromagnetism and Metamagnetism in Copper-doped Germanium Clathrate
铜掺杂的I型锗笼形物在90 K以下表现出弱磁性,包括铁磁性、反铁磁性和变磁转变。63 Cu NMR测量证实,这些转变是由于通过传导电子耦合的磁性缺陷的稀组合物,行为类似于磁性半导体。磁性测量表明局部的磁矩,归因于磁性离子簇,铁磁和反铁磁交换之间的竞争,也表明在铁磁相的玻璃态行为。核磁共振奈特位移和弛豫时间表明,导带是金属与一个大的科林加比。与平均场论的有序行为的比较给出了一个很好的解释铁磁转变。
Investigating the origin of topological-Hall-like resistivity in Zn-doped Mn2Sb ferrimagnet
East China Normal University(华东师范大学);Anhui University(安徽大学);Shanghai Institute of Technical Physics, Chinese Academy of Sciences(中国科学院上海技术物理研究所);Shanghai Jiao Tong University(上海交通大学);University of Science and Technology of China(中国科学技术大学)
The effect of vanadium substitution on the structural and magnetic properties of (Fe$_{1-x}$V$_{x}$)$_{3}$Ga$_{4}$
Fe $_{3}$ Ga $_{4}$显示出复杂的磁性相图,该相图对电子和晶体结构的变化敏感且可调。为了探索这种可调谐性,已经合成并表征了钒掺杂的(Fe $_{1-x}$ V $_{x}$)$_{3}$ Ga $_{4}$。高分辨同步辐射X射线衍射和Rietveld精修表明,当V掺杂量达到20%时,样品仍保持与Fe $_{3}$ Ga $_{4}$的等结构,并且随着掺杂量的增加,晶胞体积呈线性增加。磁性测量揭示了与V掺杂的反铁磁螺旋自旋密度波(SDW)的抑制,揭示了在低温铁磁-反铁磁(FM-AFM)转变(T $_{1}$)和高温AFM-FM转变(T $_{2}$)的变化。当V掺杂量为7.5%时,不再观察到AFM螺旋SDW相的变磁行为。这些结果提供了一个途径,以有效地调整的磁性顺序在Fe $_{3}$ Ga $_{4}$的设备,以及增加在这个系统中的磁性的理解。