Structural Stability of the Square Flux Line Lattice in YNI 2 B 2 C and LuNi 2 B 2 C Studied with Small Angle Neutron Scattering
Structural Stability of the Square Flux Line Lattice in YNI 2 B 2 C and LuNi 2 B 2 C Studied with Small Angle Neutron Scattering
复制标题
小角中子散射研究YNI 2 B 2 C和LuNi 2 B 2 C方磁通线晶格的结构稳定性
DOI：
10.1103/physrevlett.79.487
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发表时间：
1997
影响因子：
8.6
通讯作者：
P. Canfield
中科院分区：
文献类型：
--
作者：
M. Eskildsen;P. Gammel;Bradley Paul Barber;A. P. Ramirez;D. Bishop;N. Andersen;K. Mortensen;C. Bolle;Charles M. Lieber;P. Canfield
利用小角中子散射和输运研究了硼碳素超导体非磁性端元${\ mathm {YNi}}_{2}{\ mathm {B}}_{2}\ mathm {C}$和${\ mathm {LuNi}}_{2}{\ mathm {B}}_{2}\ mathm {C}$中的通量线晶格。对于字段$\mathbf{H}\ensuremath{\parallel}\mathbf{c}$，我们发现一个平方对称晶格，它在$H/{H}_{c2}\ensuremath{\sim}0.2$以上迅速失调，远低于$H/{H}_{c2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.9$的“峰值效应”。$H/{H}_{c2}l0.2$的结果可以在集体钉钉模型中理解，并由倾斜模量${c}_{44}$控制。对于$H/{H}_{c2}g0.2$，无序性似乎与剪切模量${c}_{66}$的场依赖性有关。
We have studied the flux line lattice in ${\mathrm{YNi}}_{2}{\mathrm{B}}_{2}\mathrm{C}$ and ${\mathrm{LuNi}}_{2}{\mathrm{B}}_{2}\mathrm{C}$, the nonmagnetic end members of the borocarbide superconductors using small angle neutron scattering and transport. For fields, $\mathbf{H}\ensuremath{\parallel}\mathbf{c}$, we find a square symmetric lattice which disorders rapidly above $H/{H}_{c2}\ensuremath{\sim}0.2$, well below the ``peak effect'' at $H/{H}_{c2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.9$. The results for $H/{H}_{c2}l0.2$ can be understood within the collective pinning model, and are controlled by the tilt modulus ${c}_{44}$. For $H/{H}_{c2}g0.2$, the disordering appears to be associated with the field dependence of the shear modulus, ${c}_{66}$.