Role of particle irradiation in materials science

Title : Role of particle irradiation in materials science

Abstract:

Particle irradiation is bombardment of materials with charged particles like alpha, heavy ion or neutrons. Primarily this creates various defects (like point defects like vacancy or line defects like dislocations) due to displacement of atoms. Moreover, limitations of chemical reactions arising out of thermodynamic considerations do not arise in paricle irradiation and hence one can do exotic reactions with particle irradiation. With the facility of charged particle irradiation at Variable Energy Cyclotron centre (VECC), we have carried out irradiation on variety of materials like Bi-based High Tc superconductors and have observed an increase in critical temperature (Tc) of the system. This was explained by particle irradiation induced oxygen knock out. There was also an increase in critical current density (Jc) which is having a great significance in context of application in devices. We have also carried out particle irradiation on MgB2 superconductor and observed increase in Jc.

In addition to charged particle irradiation on bulk materials, we have also undertaken heavy ion implantation on thin films of various materials like ZnO, and Ho, which have enhanced their magnetisation.     Another dimension of ion implantation is irradiation induced growth of nanostructures like nanopillars. Irradiation induced nanopillars of Ni reflected enhancement of magnetization in the direction of growth of nanopillars. The various dimensions of ion irradiation and implantation along with the mechanism of particle irradiation effevts on materials will be highlighted in the lecture.

Biography:

Dr. Sujit Kumar Bandyopadhyay is an Emeritus Fellow who served at the Meghnad Saha Institute of Technology from 2017 to 2020 and at the Institute of Engineering and Management from 2020 to 2021. He is a former Head of the Material Science Studies Division and served as Scientific Officer (H)+ and Professor at the Homi Bhabha National Institute, Variable Energy Cyclotron Centre (VECC), Department of Atomic Energy, Government of India. He retired on superannuation on 30 September 2015.

Dr. Bandyopadhyay began his career in 1978 as a Scientific Officer in the Chemical Engineering Division of the Bhabha Atomic Research Centre and joined the Variable Energy Cyclotron Centre in 1982 in the same capacity. He obtained his PhD in Physics from Jadavpur University in 1998, with a thesis titled “Charged Particle Irradiation Studies on Copper Oxide Superconductors.” In 2000, he worked as a Postdoctoral Fellow at the Atomic Institute of Austrian Universities, Vienna, focusing on magnetisation studies of neutron-irradiated high-temperature superconductor single crystals. He has been a Professor at the Homi Bhabha National Institute, a deemed university, since 2009. His achievements include the National Science Talent Search (NSTS) Scholarship and the National Scholarship from the Government of India in 1971, as well as the A. P. J. Abdul Kalam Award for outstanding research.