The magnetic entropy change (\DeltaS), a measure of the magnetocaloric effect, in Tb5Si3, a compound exhibiting unusual positive magnetoresistance following a magnetic-field-induced transition below magnetic transition temperature (~ 69 K), has been investigated. We found that \DeltaS is negative in the paramagnetic state. At the magnetic transition temperature, \DeltaS shows sign reversal from negative (in the paramagnetic state) to positive value in the magnetically ordered state. The high-field state which is interestingly the high resistive state is found to be associated with higher entropy i.e. large positive \DeltaS, behaving like a paramagnet. On the basis of this observation, we conclude that the magnetic field induces magnetic fluctuations in the system resulting in positive magnetoresistance, thereby rendering support to the idea of 'inverse metamagnetism' in this compound. In addition, we note that Arrott plots present an interesting scenario.
Correlation of exchange bias with magneto-structural effects across the compensation temperature of Co(Cr$_{1-x}$Fe$_{x}$)$_2$O$_4$ (x = 0.05 and 0.075)
Superconducting gap with sign reversal between hole pockets in heavily hole-doped Ba1-xKxFe2As2
为了深入了解铁磷族元素化物的非常规超导性，没有电子口袋，我们测量了重空穴掺杂制度的Ba $_{1-x}$ K $_x$ Fe $_2$ As $_2$的热导率$κ$和穿透深度$λ$。剩余热导率$(κ/T)_{T \rightarrow 0\,{\rm K}}$和$λ$的$T$依赖性一致地表明在$x=0.76$处的完全带隙超导性和在较高空穴浓度处的（线）节超导性。在低温下的$\fracκ{T}\cdot T_c|_{T \rightarrow 0\,{\rm K}}$和$\frac{dλ}{d(T/T_c)}$的大小，这两者都是由低能量激发的性质决定的，表现出非常不寻常的非单调x依赖性。这些结果表明，在一个狭窄的掺杂范围内的节点特性的显着变化，表明掺杂交叉的s波状态之间的间隙函数与$Γ$中心的空穴袋之间的符号反转和没有。
Magnetic and magnetotransport behavior of RFe5Al7 (R= Gd and Dy): Observation of re-entrant inverse-magnetocaloric phenomenon and asymmetric magnetoresistance behavior
Hall coefficient signals orbital differentiation in the Hund's metal Sr$_2$RuO$_4$
Sr $_2$ RuO $_4$的霍尔系数$R_H$呈现出两个符号反转的非单调温度依赖性。我们表明，这种令人费解的行为是两个交叉的签名，这是关键的物理材料。$R_H$的增加和冷却后的第一个符号变化与进入相干准粒子制度的交叉相关，该制度具有强的非弹性散射率的轨道分化。在较低温度下的最终减少和第二个符号变化是由从非弹性散射到杂质主导散射的交叉驱动的。这种定性的图片支持的定量计算$R_H(T)$使用玻尔兹曼输运理论结合动力学平均场论，考虑到自旋轨道耦合的影响。我们的见解揭示了霍尔系数的温度依赖性强轨道分化的材料，在洪德的金属中观察到的。
