DC Field | Value | Language |
dc.contributor.author | Kool, Th W. | |
dc.contributor.author | Lenjer, S. | |
dc.contributor.author | Schirmer, O. F. | |
dc.date.accessioned | 2021-12-23T16:08:41Z | - |
dc.date.available | 2021-12-23T16:08:41Z | - |
dc.date.issued | 2007 | |
dc.identifier.issn | 09538984 | |
dc.identifier.uri | https://osnascholar.ub.uni-osnabrueck.de/handle/unios/8404 | - |
dc.description.abstract | Application of uniaxial stress reveals the Jahn-Teller (JT) properties of the defect ions Ni+ (3d(9)), Rh2+ (4d(7)) and Pt3+ (5d(7)), all incorporated on Ti4+ sites in BaTiO3. In all cases the vibronic ground states are stabilized by an E circle times e Jahn-Teller effect, here leading to tetragonally elongated defect-O-6 octahedra. Orbitals of (x(2) - y(2)) type are thus lowest for the hole-like Ni+, and (3z(2) - r(2)) for the electron-like strong-field cases Rh2+ and Pt3+. The three systems are characterized by motionally averaged isotropic spectra at elevated temperatures. At low temperatures strong dependences on the distribution of internal strains are found, leading to a coexistence of isotropic averaged and quasi-static tetragonal situations for Ni+, becoming more static under uniaxial external stress. The latter behavior is also identified for Rh2+. For Rh2+ and Pt3+ the coupling of the JT systems to the external stress could be determined quantitatively, predicting rather low JT energies by a simple model calculation. The observation of tetragonal distortions of these defects thus points to the presence of regions with strong internal strains. The impurity ion Fe5+ (3d(3)), also replacing Ti4+, is found to go spontaneously off-center along [111] type directions. The defect axis orients parallel to the stress direction, indicating an axially compressed Fe5+ -O-6 oxygen arrangement in the off-center situation. | |
dc.language.iso | en | |
dc.publisher | IOP PUBLISHING LTD | |
dc.relation.ispartof | JOURNAL OF PHYSICS-CONDENSED MATTER | |
dc.subject | CAO | |
dc.subject | CRYSTALS | |
dc.subject | DOPED BARIUM-TITANATE | |
dc.subject | E-2 ORBITAL STATES | |
dc.subject | ELECTRON-PARAMAGNETIC-RESONANCE | |
dc.subject | INTERMEDIATE | |
dc.subject | MGO | |
dc.subject | OXIDE | |
dc.subject | Physics | |
dc.subject | Physics, Condensed Matter | |
dc.subject | SPECTRA | |
dc.subject | SRTIO3 | |
dc.title | Jahn-Teller and off-center defects in BaTiO3: Ni+, Rh2+, Pt3+ and Fe5+ as studied by EPR under uniaxial stress | |
dc.type | journal article | |
dc.identifier.doi | 10.1088/0953-8984/19/49/496214 | |
dc.identifier.isi | ISI:000251797700015 | |
dc.description.volume | 19 | |
dc.description.issue | 49 | |
dc.contributor.orcid | 0000-0002-2494-663X | |
dc.identifier.eissn | 1361648X | |
dc.publisher.place | TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND | |
dcterms.isPartOf.abbreviation | J. Phys.-Condes. Matter | |