Local electric field in crystals
Abstract
Matrix elements for dipole transitions of impurity centers in crystals located in an external electric field are considered, taking into account the 'effective' field in a crystal. It is shown that the usual Lorentz field approximation is generally invalid and that the effective field for impurity centers of large radius is approximately equal to the external field. A method for calculating the matrix elements is applied to a simple model, and the local Lorentz field approximation is found to be valid only in the limiting case of an infinitesimal radius for the localized electronic state. A method based on electron paramagnetic resonance (EPR) measurements in external electric fields is proposed for determining local fields in ferroelectrics. This method is illustrated by describing an experimental investigation of EPR in the virtual ferroelectric KTaO3 doped with Mn(2+).
- Publication:
-
Zhurnal Eksperimentalnoi i Teoreticheskoi Fiziki
- Pub Date:
- January 1978
- Bibcode:
- 1978ZhETF..74..164G
- Keywords:
-
- Crystal Lattices;
- Electric Fields;
- Ferroelectricity;
- Impurities;
- Lattice Parameters;
- Electric Dipoles;
- Electron Paramagnetic Resonance;
- Integral Equations;
- Lorentz Force;
- Matrices (Mathematics);
- Potassium Compounds;
- Tantalum Oxides;
- Solid-State Physics