Structure and electronic properties of the V2O3(0001) surface: ab initio density functional theory cluster studies

Electronic properties of the V2O3(0001) surface are studied using ab initio density functional theory method. In addition, the nature of surface V–O bonding as well as the electronic states of the structurally different surface oxygen and vanadium sites are discussed and compared with bulk oxygen/vanadium centers. The (0001) surface of vanadium sesquioxide is modeled using clusters of different size where the three ideal bulk-terminated surfaces, denoted as VV′O (terminated by a double layer of vanadium atoms), V′OV (terminated by one layer of V atoms), and OVV′ (terminated by one layer of oxygen atoms), are considered. For these surface terminations electronic properties of various surface and bulk centers are discussed. The results confirm bonding in vanadium sesquioxide as a mixture of ionic and covalent characters. Further, charging of structurally non-equivalent surface vanadium and oxygen sites is found to increase with the corresponding coordination number. Large differences in charging between surface and bulk vanadium atoms are found. In addition, the strong interaction between neighboring vanadium ions are observed.