Submitted on: 31 August 2011.
Revised on: 22 September 2011.
Accepted on: 04 October 2011.
Physics and Chemistry of Solid State
Submitted on: 11 May 2002.
Revised on: 05 June 2002.
Accepted on: 10 June 2002.
Physics and Chemistry of Solid State
http://reply.papertrans.cn/3/247/24662/24662-33.png
http://reply.papertrans.cn/3/247/24662/24662-34.png
http://reply.papertrans.cn/3/247/24662/24662-35.png
http://reply.papertrans.cn/3/247/24662/24662-36.png