Mondal Binita, Dan Shovan, Mondal Sudipta, Bhowmik R N, Ranganathan R, Mazumdar Chandan
Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India.
Department of Physics, The University of Burdwan, Burdwan 713104, West Bengal, India.
Phys Chem Chem Phys. 2019 Aug 21;21(31):16923-16936. doi: 10.1039/c9cp02348h. Epub 2019 Jul 24.
The binary compounds GdIr, TbIr and HoIr are synthesized successfully and found to form with macroscopic co-existence of two polymorphic phases: AuBe (C15b) and AuCu-type. The dc magnetization and heat capacity studies confirm that the C15b phase orders ferromagnetically, whereas the AuCu phase remains paramagnetic down to 2 K. The frequency dependent ac-susceptibility data, time dependent magnetic relaxation behavior and magnetic memory effect studies suggest that TbIr and HoIr are cannonical spin-glass systems, but no glassy feature could be found in GdIr. The critical behavior of all three compounds has been investigated using the magnetization and heat capacity measurements around the transition temperature (T). The critical exponents α, β, γ and δ have been estimated using different techniques such as the Arrott-Noakes plot, Kouvel-Fisher plot and critical isotherm as well as analysis of specific heat data and study of magnetocaloric effect. The critical analysis study identifies the type of universal magnetic class in which the three compounds belong.
二元化合物GdIr、TbIr和HoIr被成功合成，并发现它们由两种多晶型相宏观共存形成：AuBe（C15b）型和AuCu型。直流磁化强度和热容量研究证实，C15b相呈铁磁有序，而AuCu相在低至2 K时仍保持顺磁性。频率相关的交流磁化率数据、时间相关的磁弛豫行为以及磁记忆效应研究表明，TbIr和HoIr是典型的自旋玻璃体系，但在GdIr中未发现玻璃态特征。利用在转变温度（T）附近的磁化强度和热容量测量研究了这三种化合物的临界行为。使用不同技术，如阿罗特-诺克斯图、库维尔-费舍尔图和临界等温线，以及比热数据分析和磁热效应研究，估计了临界指数α、β、γ和δ。临界分析研究确定了这三种化合物所属的通用磁类类型。
