我们研究了具有复杂磁交换网络的非几何阻挫自旋链系统$γ$-CoV $_{2}$ O $_{6}$的磁性.我们在低温下的中子衍射图($T$ $\leqslant$ $T_{\mathrm{N}}$ = 6.6 K)最好用一个模型来描述,在这个模型中,两个磁相以65(1):35(1)的体积比共存,每个相由单个自旋调制组成。该模型比Lenertz $et$ $al$在J. Phys. Chem. C 118,13981(2014)中提出的模型更好地拟合先前的研究和我们的观察,该模型由具有两个自旋调制的一个相组成。通过从$T_{\mathrm{N}}$降低温度,我们模型的少数相在$T^{*}$ = 5.6 K处经历了一个无限-公度的锁定转变。基于这些结果,我们提出相分离是一种替代的方法,在挫折磁铁的简并提升。
英文摘要:
We have explored the magnetism in the non-geometrically frustrated spin-chain system $γ$-CoV$_{2}$O$_{6}$ which possesses a complex magnetic exchange network. Our neutron diffraction patterns at low temperatures ($T$ $\leqslant$ $T_{\mathrm{N}}$ = 6.6 K) are best described by a model in which two magnetic phases coexist in a volume ratio 65(1) : 35(1), with each phase consisting of a single spin modulation. This model fits previous studies and our observations better than the model proposed by Lenertz $et$ $al$ in J. Phys. Chem. C 118, 13981 (2014), which consisted of one phase with two spin modulations. By decreasing the temperature from $T_{\mathrm{N}}$, the minority phase of our model undergoes an incommensurate-commensurate lock-in transition at $T^{*}$ = 5.6 K. Based on these results, we propose that phase separation is an alternative approach for degeneracy-lifting in frustrated magnets.
Detection of an Unconventional Superconducting Phase in the Vicinity of the Strong First-Order Magnetic Transition in CrAs Using ^75As-Nuclear Quadrupole Resonance
Electric Pulse Induced Resistive Switching, Electronic Phase Separation, and Possible Superconductivity in a Mott insulator
金属-绝缘体转变(MIT)是一类有趣的物理现象,包括超导性和巨磁阻(CMR),它们与电阻的急剧变化有关。在过渡金属化合物中,MIT通常与强电子相关性的存在有关,强电子相关性驱动系统进入莫特绝缘体状态。在这些系统中,MIT通常通过电子掺杂或通过施加外部压力来调谐。然而,最近注意到,莫特绝缘体还应该对诸如电场的其它外部扰动敏感。我们在这里报告的第一个实验证据的非易失性电脉冲诱导的绝缘体到金属的过渡和可能的超导性的莫特绝缘体GaTa 4 Se 8。我们的扫描隧道显微镜实验表明,这种非常规的响应系统短电脉冲产生的纳米尺度的电子相分离(EPS)中产生的散装材料。