Optical and magnetic characterisation of Co<sup>3+</sup> and Ni<sup>3+</sup> in LaAlO<sub>3</sub>: interplay between the spin state and Jahn-Teller effect
| hal.structure.identifier | MALTA Consolider Team, Facultad de Ciencias | |
| dc.contributor.author | SANZ-ORTIZ, Marta N. | |
| hal.structure.identifier | MALTA Consolider Team, Facultad de Ciencias | |
| dc.contributor.author | RODRÍGUEZ, Fernando | |
| hal.structure.identifier | MALTA Consolider Team, Facultad de Ciencias | |
| dc.contributor.author | RODRÍGUEZ, Jesús | |
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | DEMAZEAU, Gérard | |
| dc.date.issued | 2011 | |
| dc.identifier.issn | 0953-8984 | |
| dc.description.abstractEn | The coordination, the electronic structures and the spin of the ground state of Ni<sup>3+</sup> (3d<sup>7</sup>) and Co<sup>3+</sup> (3d<sup>6</sup>) introduced as impurities in LaAlO<sub>3</sub> are investigated through optical spectroscopy and magnetic measurements. The unusual trivalent valence state in both transition-metal ions was stabilised via a sol-gel process followed by high oxygen pressure treatments. We show that the crystal-field strength at the nearly O<sub>h</sub> transition-metal site in LaAlO<sub>3</sub> locates Ni<sup>3+</sup> and Co<sup>3+</sup> near the spin state crossover, yielding a low-spin ground state in both cases. We analyse how the interplay between the Jahn-Teller (JT) effect and the spin state affects the magnetic moment of the ion and its temperature dependence. The optical spectra reveal a JT effect associated with a low-spin ground state in Ni<sup>3+</sup> and with a thermally populated high-spin low-lying first excited state in Co<sup>3+</sup>. The corresponding JT distortions are derived from structural correlations. We conclude that the JT effect is unable to stabilise the intermediate spin state in Co<sup>3+</sup>. A low-spin ground state in thermal equilibrium with a high-spin low-lying first excited state is detected in diluted Co<sup>3+</sup>-doped LaAlO<sub>3</sub>. These results are compared with those obtained in the parent pure compounds LaNiO<sub>3</sub> and LaCoO<sub>3</sub>. | |
| dc.language.iso | en | |
| dc.publisher | IOP Publishing | |
| dc.subject.en | Inorganic compounds | |
| dc.subject.en | Jahn-Teller effect | |
| dc.subject.en | Crystal impurities | |
| dc.subject.en | Spin | |
| dc.subject.en | Lanthanum | |
| dc.subject.en | Oxides | |
| dc.title.en | Optical and magnetic characterisation of Co<sup>3+</sup> and Ni<sup>3+</sup> in LaAlO<sub>3</sub>: interplay between the spin state and Jahn-Teller effect | |
| dc.type | Article de revue | |
| dc.identifier.doi | 10.1088/0953-8984/23/41/415501 | |
| dc.subject.hal | Chimie/Matériaux | |
| bordeaux.journal | Journal of Physics: Condensed Matter | |
| bordeaux.page | 415501 (6 p.) | |
| bordeaux.volume | 23 | |
| bordeaux.issue | 41 | |
| bordeaux.peerReviewed | oui | |
| hal.identifier | hal-00636362 | |
| hal.version | 1 | |
| hal.popular | non | |
| hal.audience | Internationale | |
| hal.origin.link | https://hal.archives-ouvertes.fr//hal-00636362v1 | |
| bordeaux.COinS | ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Journal%20of%20Physics:%20Condensed%20Matter&rft.date=2011&rft.volume=23&rft.issue=41&rft.spage=415501%20(6%20p.)&rft.epage=415501%20(6%20p.)&rft.eissn=0953-8984&rft.issn=0953-8984&rft.au=SANZ-ORTIZ,%20Marta%20N.&RODR%C3%8DGUEZ,%20Fernando&RODR%C3%8DGUEZ,%20Jes%C3%BAs&DEMAZEAU,%20G%C3%A9rard&rft.genre=article |
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