Key;
Laboratory;
of;
Material;
Physics,;
Ministry;
of;
Education,;
Zhengzhou;
University,;
Zhengzhou;
450052,;
China;
School;
of;
Material;
Science;
and;
Engineering,;
Henan;
University;
of;
Science;
and;
Technology,;
Luoyang;
471003,;
China;