Centre of High Pressure Research, School of Physics, Bharathidasan University, Tiruchirappalli, 620024, India.
Discipline of Metallurgy Engineering and Materials Science & Physics, Indian Institute of Technology Indore, Simrol Campus, Khandwa road, Indore, 453552, India.
Sci Rep. 2018 Jan 19;8(1):1251. doi: 10.1038/s41598-018-19636-z.
The impact of hydrostatic pressure (P) up to 1 GPa on T , J and the nature of the pinning mechanism in FeNbSe single crystals have been investigated within the framework of the collective theory. We found that the pressure can induce a transition from the regime where pinning is controlled by spatial variation in the critical transition temperature (δT ) to the regime controlled by spatial variation in the mean free path (δℓ). Furthermore, T and low field J are slightly induced, although the J drops more rapidly at high fields than at ambient P. The pressure effect enhances the anisotropy and reduces the coherence length, resulting in weak interaction of the vortex cores with the pinning centers. Moreover, the P can induce the density of states, which, in turn, leads to enhance in T with increasing P. P enhances the T with the rates of dT /dP of 0.86, 1.35 and 1.47 K/GPa for FeNbSe, respectively. The magnetization data are used to establish a vortex phase diagram. The nature of the vortices has been determined from the scaling behaviour of the pinning force density extracted from the J -H isotherms and demonstrates the point pinning mechanism.
在集体理论的框架内，研究了静水压力（P）高达 1GPa 对 FeNbSe 单晶中的 T 、 J 以及钉扎机制性质的影响。我们发现，压力可以诱导从由临界转变温度（δT ）的空间变化控制钉扎的状态转变为由平均自由程（δℓ）的空间变化控制钉扎的状态。此外，尽管在高场时 J 比环境 P 下降得更快，但 T 和低场 J 略有增加。压力效应增强了各向异性并减小了相干长度，从而导致涡旋核与钉扎中心的相互作用减弱。此外，压力可以诱导态密度，进而导致 T 随 P 的增加而增加。P 以分别为 0.86、1.35 和 1.47 K/GPa 的速率增强 T 。磁化数据用于建立涡旋相图。从从 J -H 等离体中提取的钉扎力密度的标度行为确定了涡旋的性质，并证明了点钉扎机制。
