Theoretical investigation of the local lattice structure of Mn<Superscript> 2+</Superscript> ion doped in tetragonal K<Subscript> 2</Subscript>ZnF<Subscript> 4</Subscript> crystal
The complete energy matrices<InlineEquation ID="Equ1"> <EquationSource Format="TEX">$\left( {252\times 252} \right)$</EquationSource> </InlineEquation> for a d<Superscript>5</Superscript>configuration ion in a tetragonal ligand-field has been constructed on the basis of the complete set of basis <InlineEquation ID="Equ2"> <EquationSource Format="TEX">$\left| {L,S,M_L ,M_S } \right\rangle $</EquationSource> </InlineEquation> of d<Superscript>5</Superscript>configuration (252 dimension), and the relationship between the low-symmetry EPR parameters b<Subscript>2</Subscript> <Superscript>0</Superscript> ,b<Subscript>4</Subscript> <Superscript>0</Superscript> and the local distortion parameters has been established based on the complete energy matrices. As an application, we have studied the EPR parameters and the local lattice structure of Mn<Superscript>2+</Superscript> ion doped in tetragonal K<Subscript>2</Subscript>ZnF<Subscript>4</Subscript> system. The calculation indicated that the local lattice structure around a tetragonal Mn<Superscript>2+</Superscript> ion center has an expansion distortion. Simultaneously, the local lattice structure parameters R<Subscript>1</Subscript> =2.0727 Å, R<Subscript>2</Subscript> =2.0801 Å at room temperature (295 K) and R<Subscript>1</Subscript> <Superscript>′</Superscript>=2.0439 Å, R<Subscript>2</Subscript> <Superscript>′</Superscript> =2.05478 Å at low temperature (4.2 K) are determined. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2006
