Xu Diming, Liu Zhibo, Li Xiao, Avdeev Maxim, Zhou Ke-Hong, Li Jun, Tan KarBan, Meng Yin-Shan, Zhou Tao, Zhou Di
School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
Electronic Materials Research Laboratory, Key Laboratory of Multifunctional Materials and Structures, Ministry of Education, Xi'an Jiaotong University, Xi'an, 710049, China.
Dalton Trans. 2025 Aug 19;54(33):12689-12699. doi: 10.1039/d5dt01289a.
Metamagnetism represents a distinctive subclass within the antiferromagnetic (AFM) regime, exhibiting significant potential for diverse technological applications, particularly in magnetocaloric effects. In this paper, we systematically investigate the magnetic-field-induced phase transition in RFeCuGeO (R = Tm-Lu) through comprehensive temperature-dependent and field-dependent magnetization measurements and neutron powder diffraction (NPD) analysis. Our experimental results demonstrate an AFM transition at ∼18, 13 and 13.5 K of Tm, Yb and Lu, respectively, but the magnetic-field-induced phase transition was only seen in Tm at ∼1.8 T (2 K). NPD refinements elucidate that the metamagnetic transition corresponds to A-type antiferromagnetic ordering at zero-field and a ferromagnetic (FM) structure emerges under high magnetic fields, with magnetic moments aligned along the -axis; for R = Yb and Lu, A + G-type AFM and A + C-type AFM structures were observed. Our findings suggest that the anisotropic cation Cu plays a crucial role in mediating the metamagnetic behavior, while the A-site cation significantly influences the internal molecular field and subsequently the metamagnetic behavior. These results provide valuable insights into the fundamental mechanisms governing metamagnetic transitions in complex oxide systems or multimetallic oxide systems.
变磁性是反铁磁（AFM）体系中的一个独特子类，在各种技术应用中具有巨大潜力，尤其是在磁热效应方面。在本文中，我们通过全面的温度相关和磁场相关磁化测量以及中子粉末衍射（NPD）分析，系统地研究了RFeCuGeO（R = Tm - Lu）中磁场诱导的相变。我们的实验结果表明，Tm、Yb和Lu分别在约18 K、13 K和13.5 K发生AFM转变，但仅在Tm中约1.8 T（2 K）时观察到磁场诱导的相变。NPD精修表明，变磁转变对应于零场下的A型反铁磁有序，在高磁场下出现铁磁（FM）结构，磁矩沿 - 轴排列；对于R = Yb和Lu，观察到A + G型AFM和A + C型AFM结构。我们的研究结果表明，各向异性阳离子Cu在介导变磁行为中起关键作用，而A位阳离子显著影响内部分子场，进而影响变磁行为。这些结果为复杂氧化物体系或多金属氧化物体系中变磁转变的基本机制提供了有价值的见解。
