Structural instability and lattice site occupation of Mn2+ ions in the SrTiO3 quantum paraelectric

Structural instability and lattice site occupation of Mn2+ ions in the SrTiO3 quantum paraelectric

Článek WoS

Strontium titanate (SrTiO3) is the most known material from the family of quantum paraelectrics. Thanks to its extremely "soft" lattice, its functionality can be easily tuned by applying both external stimuli (pressure, strain, electric field) and through doping or isotope exchange. In this paper, we present the results of a detailed study of two Mn2+ centers in Mn-doped SrTiO3 single crystals using both continuous wave and pulsed electron paramagnetic resonance (EPR) spectroscopy at frequencies from 9.5 to 427 GHz and temperatures from 5 to 296 K. The first center is created by a Mn2+ ion at the Sr2+ lattice site in an off-center position. Its spectroscopic characteristics were determined for both fast and slow motion regimes of the impurity ion. In particular, all spin transitions allowed by the Mn2+ spin were well resolved in the slow motion regime. The second center is created by a Mn2+ ion at the Ti4+ position in the center of the oxygen octahedron. It has been established that the surrounding of this ion undergoes strong distortion when cooled below the phase transition temperature Tc = 105 K, stimulated by the rotation of the oxygen octahedron. The present data also perfectly explain the previously obtained EPR data from measurements of SrTiO3:Mn ceramics at low microwave frequencies (9-10 GHz).

Strontium titanate (SrTiO3) is the most known material from the family of quantum paraelectrics. Thanks to its extremely "soft" lattice, its functionality can be easily tuned by applying both external stimuli (pressure, strain, electric field) and through doping or isotope exchange. In this paper, we present the results of a detailed study of two Mn2+ centers in Mn-doped SrTiO3 single crystals using both continuous wave and pulsed electron paramagnetic resonance (EPR) spectroscopy at frequencies from 9.5 to 427 GHz and temperatures from 5 to 296 K. The first center is created by a Mn2+ ion at the Sr2+ lattice site in an off-center position. Its spectroscopic characteristics were determined for both fast and slow motion regimes of the impurity ion. In particular, all spin transitions allowed by the Mn2+ spin were well resolved in the slow motion regime. The second center is created by a Mn2+ ion at the Ti4+ position in the center of the oxygen octahedron. It has been established that the surrounding of this ion undergoes strong distortion when cooled below the phase transition temperature Tc = 105 K, stimulated by the rotation of the oxygen octahedron. The present data also perfectly explain the previously obtained EPR data from measurements of SrTiO3:Mn ceramics at low microwave frequencies (9-10 GHz).

ELECTRON-PARAMAGNETIC-RESONANCE; SPIN-RESONANCE; MANGANESE; PHASE; STRONTIUM; FERROELECTRICITY; TRANSITIONS; EPR

ELECTRON-PARAMAGNETIC-RESONANCE; SPIN-RESONANCE; MANGANESE; PHASE; STRONTIUM; FERROELECTRICITY; TRANSITIONS; EPR

LAGUTA, O.; NEUGEBAUER, P.; ZDEG, I.; LAGUTA, V.

2025

30.07.2024

AMER PHYSICAL SOC

COLLEGE PK

2469-9950

PHYSICAL REVIEW B

110

2

Spojené státy americké

9

https://journals.aps.org/prb/abstract/10.1103/PhysRevB.110.024114