arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 0910.0519cond-mat.str-el
收藏

交叉弛豫和声子瓶颈效应对LiYF4:Ho3 +磁化动力学的影响

Cross-relaxation and phonon bottleneck effects on magnetization dynamics in LiYF4:Ho3+

S. Bertaina, B. Barbara, R. Giraud, B. Z. Malkin, M. V. Vanuynin, A. I. Pominov, A. L. Stolov, A. M. Tkachuk

摘要:

在液氦温度下,在平行于四方晶系对称轴的交流和直流磁场中,测量了稀释顺磁体$_4$:Ho $^{3+}$的动态磁化率随频率和直流磁场的变化.在弛豫速率的微观理论框架下,分析了Ho $^{3+}$基态多重态$^5I_8$中最低非Kramers双重态和第一激发单重态的24个电子核子能级的流形中S $_4$对称性晶场分裂的弛豫速率.利用在交换电荷模型框架下计算的电子-声子耦合常数计算了单声子跃迁几率,并通过光学压谱测量进行了检验。当考虑声子瓶颈效应和交叉自旋弛豫时,模拟很好地再现了在电子-核子能级的交叉点(反交叉点)处的同相和异相磁化率(分别为驼峰和凹陷)随场变化的具体特征.

英文摘要:

Frequency and dc magnetic field dependences of dynamic susceptibility in diluted paramagnets LiYF$_4$:Ho$^{3+}$ have been measured at liquid helium temperatures in the ac and dc magnetic fields parallel to the symmetry axis of a tetragonal crystal lattice. Experimental data are analyzed in the framework of microscopic theory of relaxation rates in the manifold of 24 electron-nuclear sublevels of the lowest non-Kramers doublet and the first excited singlet in the Ho$^{3+}$ ground multiplet $^5I_8$ split by the crystal field of S$_4$ symmetry. The one-phonon transition probabilities were computed using electron-phonon coupling constants calculated in the framework of exchange charge model and were checked by optical piezospectroscopic measurements. The specific features observed in field dependences of the in- and out-of-phase susceptibilities (humps and dips, respectively) at the crossings (anti-crossings) of the electron-nuclear sublevels are well reproduced by simulations when the phonon bottleneck effect and the cross-spin relaxation are taken into account.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑