The tetragonal elastic dipole Cr5+ in SrTiO3

Tetragonal Cr⁵⁺ impurity centre in single crystals of the perovskite SrTiO₃. After careful analyses we came to the conclusion that this centre is an off-centre system and no Jahn-Teller impurity. From the previous stress experiments in EPR we calculated the linear stress coupling tensor as β = 3.56×10^-30 m³, which is in agreement with other stress coupling tensors of off-centre systems in SrTiO₃ as well as BaTiO₃.

The tetragonal elastic dipole Cr5+ in SrTiO3

Tetragonal Cr⁵⁺ impurity centre in single crystals of the perovskite SrTiO₃. After careful analyses we came to the conclusion that this centre is an off-centre system and no Jahn-Teller impurity. From the previous stress experiments in EPR we calculated the linear stress coupling tensor as β = 3.56×10^-30 m³, which is in agreement with other stress coupling tensors of off-centre systems in SrTiO₃ as well as BaTiO₃.

The tetragonal elastic dipole Cr5+ in SrTiO3

Tetragonal Cr⁵⁺ impurity centre in single crystals of the perovskite SrTiO₃. After careful analyses we came to the conclusion that this centre is an off-centre system and no Jahn-Teller impurity. From the previous stress experiments in EPR we calculated the linear stress coupling tensor as β = 3.56×10^-30 m³, which is in agreement with other stress coupling tensors of off-centre systems in SrTiO₃ as well as BaTiO₃.

Renormalised Perturbative Series for the Impurity Levels in a Quantum Well

The energy levels of an impurity centre in a quantum well of width L and depth g are studied analytically . Renormalised perturbative series are constructed in the regions g L2≪1 and gL2≫1. The universal behavior of the energy in each regime is stressed. Similar results can be obtained for the impurity in a quantum wire, in a dot or in a multiwell structure.