Rousochatzakis I, Ajiro Y, Mitamura H, Kögerler P, Luban M
Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.
Phys Rev Lett. 2005 Apr 15;94(14):147204. doi: 10.1103/PhysRevLett.94.147204. Epub 2005 Apr 13.
We have observed hysteresis loops and abrupt magnetization steps in the magnetic molecule {V(6)}, where each molecule comprises a pair of identical spin triangles, in the temperature range 1-5 K for external magnetic fields B with sweep rates of several Tesla per millisecond executing a variety of closed cycles. The hysteresis loops are accurately reproduced using a generalization of the Bloch equation based on direct one-phonon transitions between the instantaneous Zeeman-split levels of the ground state (an S=1/2 doublet) of each spin triangle. The magnetization steps occur for B approximately 0, and they are explained in terms of adiabatic Landau-Zener-Stückelberg transitions between the lowest magnetic energy levels as modified by an intertriangle anisotropic exchange of order 0.4 K.
我们在磁性分子{V(6)}中观测到了磁滞回线和突变的磁化台阶，其中每个分子由一对相同的自旋三角形组成，在1至5 K的温度范围内，对于扫速为每毫秒几特斯拉的外磁场B执行各种闭合循环。利用基于每个自旋三角形基态（一个S = 1/2双重态）的瞬时塞曼分裂能级之间直接单声子跃迁的布洛赫方程推广，可精确再现磁滞回线。磁化台阶出现在B约为0时，它们是根据由约0.4 K的三角形间各向异性交换所修正的最低磁能级之间的绝热朗道 - 齐纳 - 施图克尔贝格跃迁来解释的。
