Electronic and structural properties of orthorhombic KTiOPO4 and related isomorphic materials

Abstract

Ab-initio electronic structure calculations using the local density (LDA) and generalized gradient approximations (GGA) are undertaken on Potassium Titanyl Phosphate (KTP) and isomorphic materials. The crystal structure is better predicted using one of the GGA approximations. The affect of Rb replacing K on the essential TiO6 and PO4 blocks of the alloyed system are investigated as are affects of AsO4 replacing PO 4. It is observed that the asymmetry in the K-Rb alloy very slightly affects the electronic properties of the material. Electronic charge density distributions clearly show the cation conduction channels, with changes found to occur between the different structural isomorphs. A calculated density of electronic states shows the importance of Ti-O interactions around the Fermi energy that lead to important laser properties. © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.