Swift Heavy Ion Beam Modified Behaviour of Pure and Doped TGS Crystals

Modifications due to swift heavy ion (SHI) beam irradiation on polar surfaces of pure and doped tri-glycine sulphate (TGS) crystals are investigated using dielectric, ferroelectric, optical and scanning force microcopy with varying ion beam fluence. The dielectric response becomes diffuse and the loss decreases, the optical band gap gets modified, the surface micro-relief's show pits and protrusions converting into regular hillocks of nano-dimensions. The results are interpreted considering that irradiation takes the crystal to a non-equilibrium state and generates thermal/charge flux leading to thermally generated internal field. The micro-relief is explained as a result of domain orientation; piezoelectric compression and stretching creating inhomogeneous force gradient at domain walls.