1. Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai-400 085, India
2. Homi Bhabha National Institute, Anushaktinagar, Mumbai-400 094, India
3. Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai-400 085, India
4. Chemistry Division, Bhabha Atomic Research Centre, Mumbai-400 085, India