1. Department
of Physics, St. Mary’s Group of Institutions Guntur, Guntur, Andhra Pradesh 522212, India
2. Department
of Physics, Vasireddy Venkatadri Institute of Technology, Nambur, Andhra Pradesh 522508, India
3. Department of Physics, Nalanda Institute of Engineering & Technology, Sathenapalli, Andhra Pradesh 522438, India
4. Department of Physics, VSR & NVR College, Tenali, Andhra Pradesh 522201, India