%0 Journal Article
%T Magnetic Quantum Tunnelling in Faster Relaxation Process in Mn12Ac Molecular Magnets
%A LIU Hai-Qing
%A SU Shao-Kui
%A JING Xiu-Nian
%A LIU Ying
%A HE Lun-Hua
%A GE Pei-Wen
%A YAN Qi-Wei
%A WANG Yun-Ping
%A <br>刘海青
%A 苏少奎
%A 景秀年
%A 刘颖
%A 何伦华
%A 葛培文
%A 严启伟
%A 王云平
%J 中国物理快报
%D 2007
%I 
%X The field-tuned ac susceptibility of Mn12Ac single crystal has been measured as functions of temperature and frequency. Two relaxation processes appear in our measurement. One is related to the magnetic quantum tunnelling of a collective spin S = 12 by a 61 K magnetic barrier and it has been well studied, while the other is faster than the former and its mechanism is unclear. We find that the relaxation time for the faster process shows the minima at H = 0 and H = 3.4 kOe, indicating that the quantum tunnelling also takes place in this process while the resonant fields are different from what we have known before.
%K 75
%K 45
%K +j
%K 75
%K 50
%K Xx
%K 73
%K 43
%K Jn<br>量子理论
%K 隧道效应
%K 磁性
%K 松弛过程
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=47EA7CFDDEBB28E0&jid=E27DA92E19FE279A273627875A70D74D&aid=A6F1F92187EC7BB80240039C522FA702&yid=A732AF04DDA03BB3&vid=B91E8C6D6FE990DB&iid=0B39A22176CE99FB&sid=640CCB6E396307A8&eid=A726E84831FE609B&journal_id=0256-307X&journal_name=中国物理快报&referenced_num=0&reference_num=0