Static magnetic properties of ( CH 3 ) 4 N Mn x Cu 1 − x Cl 3 , a quantum ferromagnetic chain with classical impurities: Experiment and theory
Static magnetic properties of ( CH 3 ) 4 N Mn x Cu 1 − x Cl 3 , a quantum ferromagnetic chain with classical impurities: Experiment and theory
复制标题
DOI：
10.1103/physrevb.25.3261
复制
发表时间：
1982-03
影响因子：
3.7
通讯作者：
C. Dupas;J. Renard;J. Seiden;A. Cheikh-rouhou
中科院分区：
文献类型：
--
作者：
C. Dupas;J. Renard;J. Seiden;A. Cheikh-rouhou
The magnetic susceptibility of the mixed quasi-one-dimensional system ${({\mathrm{CH}}_{3})}_{4}\mathrm{N}{\mathrm{Mn}}_{x}{\mathrm{Cu}}_{1\ensuremath{-}x}{\mathrm{Cl}}_{3}$ has been measured down to 0.32 K for $x$ ranging between 0 and 1. At 4.2 K the susceptibility starts to increase with $x$ up to $x\ensuremath{\simeq}0.1$ and then decreases rapidly. The N\'eel temperature decreases from 1.24 K for $x\ensuremath{\simeq}0$ to 0.35 K for $x=0.22$. We present theoretical calculations developed for isotropic exchange interactions and we take into account the quantum and classical natures of the ${\mathrm{Cu}}^{2+}$ and ${\mathrm{Mn}}^{2+}$ spins, respectively. We show that to first order in $x$ the problem of the disorder inside the chains can be reduced to the calculation of a transfer matrix. This matrix is calculated at high temperature as a function of a parameter $v$ which can be determined by a more rigorous calculation made in the case of diamagnetic impurities and at lower temperatures. The experimental data at small values of $x$ are well explained by this model.
The magnetic susceptibility of the mixed quasi-one-dimensional system ${({\mathrm{CH}}_{3})}_{4}\mathrm{N}{\mathrm{Mn}}_{x}{\mathrm{Cu}}_{1\ensuremath{-}x}{\mathrm{Cl}}_{3}$ has been measured down to 0.32 K for $x$ ranging between 0 and 1. At 4.2 K the susceptibility starts to increase with $x$ up to $x\ensuremath{\simeq}0.1$ and then decreases rapidly. The N\'eel temperature decreases from 1.24 K for $x\ensuremath{\simeq}0$ to 0.35 K for $x=0.22$. We present theoretical calculations developed for isotropic exchange interactions and we take into account the quantum and classical natures of the ${\mathrm{Cu}}^{2+}$ and ${\mathrm{Mn}}^{2+}$ spins, respectively. We show that to first order in $x$ the problem of the disorder inside the chains can be reduced to the calculation of a transfer matrix. This matrix is calculated at high temperature as a function of a parameter $v$ which can be determined by a more rigorous calculation made in the case of diamagnetic impurities and at lower temperatures. The experimental data at small values of $x$ are well explained by this model.