Electronic Properties of Ternary Compounds with Vacancy Clusters: ab initio Simulation

Electronic and magnetic properties of ternary crystal TlMeX2 compound (TlGaS2 as an example) with alone vacancy or their clusters were studied by means of first-principle (ab initio) approximation. It was shown that presence of S-vacancy clusters narrows the band gap of TlGaS2 crystal significantly while Tl - vacancy clusters increase it slightly. Restructuring TlGaS2 crystal due to vacancy or vacancy clusters presence leads to manifestation of ferromagnetic properties of the compound with the spin polarization value approx. 22 % when the number of vacancies in the cluster increases up to extremely high values. Revealed phenomena may be used in the censoring applications.