1
Materials Science Group, Department of Physics, Chemistry, and Mathematics Alabama A&M University, Normal (Huntsville), AL 35762, USA
2
Department of Physics, Sree Kerala Varma College, Thrissur, Kerala 680011, India
3
Department of Mechanical, Civil Engineering and Construction Management Alabama A&M University, Normal (Huntsville), AL 35762, USA
1
Tel.: 2563728109, fax: 2563725622
E-mail:
ashok.batra@aamu.edu