Pramanick S, Dutta P, Sannigrahi J, Mandal K, Bandyopadhyay S, Majumdar S, Chatterjee S
UGC-DAE Consortium for Scientific Research, Kolkata Centre, Sector III, LB-8, Salt Lake, Kolkata 700 098, India.
J Phys Condens Matter. 2018 Oct 10;30(40):405803. doi: 10.1088/1361-648X/aaddd7. Epub 2018 Aug 30.
We report detailed investigations on the structural, magnetic, magneto-transport and calorimetric aspects of a partially ordered Heusler compound PdMnIn. The sample shows antiferomagnetic (AFM) state below around 120 K, though positive paramagnetic Curie temperature signifies a complex magnetic ground state with the presence of both ferromagnetic (FM) and AFM correlations. A clear spin-flop type metamagnetic transition is observed as evident from the magnetization and resistivity data. However, non-saturation of magnetization even at 145 kOe of applied field implies that the high field state may be a spin canted state, originating from the enhanced FM correlations by field induced conduction electron spin polarization. The sample shows a profound quadratic temperature dependence of resistivity below about 20-25 K indicating a spin-fluctuation dominated low temperature region. Previous electronic structure calculations show the existence of a subtle balance between superexchange mediated AFM state and an RKKY (Ruderman-Kittel-Kasuya-Yoshida) interaction mediated FM state in PdMnIn. Such competing AFM-FM correlations can be accounted for the observed spin fluctuations.
我们报告了对部分有序的赫斯勒化合物PdMnIn的结构、磁性、磁输运和量热方面的详细研究。该样品在约120 K以下呈现反铁磁（AFM）状态，尽管正的顺磁居里温度表明存在具有铁磁（FM）和AFM相关性的复杂磁性基态。从磁化强度和电阻率数据可以明显观察到清晰的自旋翻转型变磁转变。然而，即使在145 kOe的外场下磁化强度也未饱和，这意味着高场状态可能是自旋倾斜状态，这是由场致传导电子自旋极化增强的FM相关性引起的。该样品在约20 - 25 K以下显示出电阻率对温度的深刻二次依赖性，表明低温区域以自旋涨落为主。先前的电子结构计算表明，在PdMnIn中，超交换介导的AFM状态与RKKY（鲁德曼 - 基特尔 - 卡苏亚 - 吉田）相互作用介导的FM状态之间存在微妙的平衡。这种竞争的AFM - FM相关性可以解释观察到的自旋涨落。
