Electronic, mechanical, optical and piezoelectric properties of glass like sodium silicate (Na 2 SiO 3 ) under compressive pressure
AbstractStructural, mechanical, electronic, optical and piezoelectric properties of Na 2 SiO 3 are studied under different compressive uni-directional pressure(0-50 GPa with a difference of 10 GPa) using density functional theory (DFT). The calculated structural properties are well agreed with the previously reported results. At 12 GPa, our calculation shows structural phase transition from orthorhombic Cmc2 1 to triclinic P1. The mechanical profile of Na 2 SiO 3 structures under different compressive unidirectional pressures are analysed by calculating the elastic moduli, Poisson's ratio and eigenvalues of stiffness matrix. Our study shows mechanical stability of the system till pressure reaches 40 GPa. Herein, we have obtained an indirect band gap of 2.97 eV at 0 GPa. Between 0-50 GPa, the band gaps are within the range of 2.62 to 3.46 eV. The system under our study possesses wide band gap and high optical absorption in UV-Vis range of electro-magnetic(em) radiation. The calculated static refractive indices η x,y,z (0) are closed to unity suggesting its transparent behaviour. For piezoelectric properties, we have reported the total Cartesian polarization. Our calculations have revealed that Na 2 SiO 3 to be one of the promising candidates for opto-electronic devices while its application in ferroelectric and piezoelectric devices could be improved with further research.