Two-dimensional magnetic interplay in the tensile-strained LaCoO3 thin films.
Two-dimensional magnetic interplay in the tensile-strained LaCoO3 thin films.
复制标题
DOI：
10.1039/d0cp05550f
复制
发表时间：
2021-02
期刊：
影响因子：
--
通讯作者：
Hao Liu;Jiyu Fan;F. Qian;Yanda Ji;A. Rahman;R. Tang;Lei Zhang;L. Ling;Yan Zhu;Hao Yang
中科院分区：
文献类型：
--
作者：
Hao Liu;Jiyu Fan;F. Qian;Yanda Ji;A. Rahman;R. Tang;Lei Zhang;L. Ling;Yan Zhu;Hao Yang
采用脉冲激光沉积法（PLD）在SrTiO 3（STO）衬底上制备了高质量的LaCoO 3（LCO）外延薄膜。结果表明，LCO薄膜在1080 K时发生了典型的铁磁-顺磁（FM-PM）相变。为了解磁相变的本质，采用修正的Arrott图和临界等温线分析等方法，测定了磁相变的临界指数：β = 0.754（1），居里温度TC = 79.8（8）K; γ = 1.52（2），居里温度TC = 79.9（2）K。利用Widom标度关系和标度假设对这些临界指数的可靠性进行了验证。进一步的分析表明，LCO薄膜内部的自旋耦合表现出二维（2D）长程磁相互作用，磁交换距离随J（r）= 3.46衰减。我们的临界行为分析可能会为进一步理解LCO薄膜中FM的起源和相对固定的TC提供新的思路。
High-quality epitaxial LaCoO3 (LCO) thin films have been deposited on SrTiO3 (STO) substrates with pulsed laser deposition (PLD). We find that the LCO films undergo a typical ferromagnetic-paramagnetic (FM-PM) phase transition at ∼80 K. To understand the nature of magnetic phase transition, various methods, including the modified Arrott plot and critical isotherm analysis, were used to determine the critical exponents, which are β = 0.754(1) with a Curie temperature TC = 79.8(8) K and γ = 1.52(2) with TC = 79.9(2) K. The reliability of these critical exponents was confirmed using the Widom scaling relation and the scaling hypothesis. Further analysis revealed that the spin coupling within the LCO films exhibits two-dimensional (2D) long-range magnetic interaction and the magnetic exchange distance decays as J(r) ∼ r-(3.46). Our critical behavior analysis may shed new light on the further understanding of the origin of FM and the relatively fixed TC in LCO thin films.