Elastic and electronic properties of MnTi2O4 under pressure: A first-principle study

Zhang, T.; Lv, Zhen‐Long; Chen, Yan; Chen, X.R.; Ji, Guang Fu

doi:10.1016/j.commatsci.2013.12.017

Cited by 9 publications

(4 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…smaller than the closest cubic F d-3m structure). Between the cubic F d-3m structure and tetragonal I 4 1 /amd structure of MnTi 2 O 4 , F d-3m structure is found to have lower energy, which is in consistence with the earlier report [19]. The obtained ground-state P 4 1 structure of MnTi 2 O 4 consists of two inequivalent Ti sites (as shown in Fig.…”

supporting

confidence: 86%

“…As this is unusual, we use a combination of theory and experiments to explore the driving mechanism for the orbital ordering. The ground-state lattice and magnetic structure of MnTi 2 O 4 , however, remains contentious [17][18][19]. We elucidate that the ferrimagnetic tetragonal P 4 1 structure is the ground-state of MnTi 2 O 4 and show that this structure hosts a unique combination of tetramer OO, lattice-chiralilty and spontaneous electric polarization.…”

mentioning

confidence: 99%

“…The pre-processing and fitting of EXAFS data were carried out over the k -range of 3-12 Å−1 using ATHENA and ARTEMIS softwares [27]. Cubic F d-3m as well as tetragonal I 4 1 /amd (which is a simple elongation of cubic F d-3m along the c-axis) structures have been proposed to be the ground state of MnTi 2 O 4 [17][18][19]. We, however, find that the ferrimagnetic P 4 1 tetragonal structure possesses the lowest energy (56 meV/f.u.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Tetramer orbital ordering and lattice chirality in MnTi2O4

et al. 2019

View full text Add to dashboard Cite

Using density-functional theory calculations and experimental investigations on structural, magnetic and dielectric properties, we have elucidated a unique tetragonal ground state for MnTi2O4, a Ti 3+ (3d 1 )-ion containing spinel-oxide. With lowering of temperature around 164 K, cubic MnTi2O4 undergoes a structural transition into a polar P 41 tetragonal structure and at further lower temperatures, around 45 K, the system undergoes a paramagnetic to ferrimagnetic transition. Magnetic superexchange interactions involving Mn and Ti spins and minimization of strain energy associated with co-operative Jahn-Teller distortions plays a critical role in stabilization of the unique tetramer-orbital ordered ground state which further gives rise to lattice chirality through subtle Ti-Ti bond-length modulations. PACS numbers: 71.15.Mb, 61.10.Nz, 61.10.Ht, 52.70.Ds Transition-metal (TM) oxides with orbital degrees of freedom constitute a fascinating field of research and hosts copious physical phenomena, which include high-temperature superconductivity, colossal magnetoresistance and multiferroicity [1][2][3]. In transition metal oxides with strong electronelectron correlations, electrons are primarily localized on the atoms. Exotic physics ensue when such localized electrons also possess orbital degrees of freedom, i.e. electrons can choose to occupy between a set of equivalent and energydegenerate atomic orbitals. Octahedrally coordinated Mn 3+ ions in LaMnO 3 with 3d 4 (t 32g -e 1 g ) configuration constitutes a representative example, where a single electron has a choice to occupy any of the two degenerate e g orbitals. Often at a lower temperature, the electron chooses one from the two e g orbitals, which breaks the local charge symmetry and is accompanied by differential oxygen-ion displacements, referred to as Jahn-Teller (JT) distortion. In a solid, such choices on different atoms are inter-dependent, which results into cooperative JT distortions associated with a spontaneous orbitalordering (OO) transition, wherein localized occupied orbitals on various ions form a regular pattern [2,[4][5][6]. Similar to the e g OO systems, transition-metal oxides constituting ions possessing t 2g -level orbital degrees of freedom, such as in YTiO 3 (one Ti 3+ d electron in a subspace of three degenerate t 2g orbitals) [7,8], MnV 2 O 4 (two V 3+ d electrons among three degenerate t 2g orbitals) [9][10][11], also exhibit cooperative JT distortions and various OO ground states. Mostly, in these TM systems, either a ferro-OO state (similar occupied orbital at all ionic sites) or an antiferro-OO state (with alternate ions occupied by similar orbitals), or a combination of the two along different directions is realized. The presence of higher-order OO has very few examples, such as CuIr 2 S 4 [12, 13] and Fe 3 O 4 [14-16], and unlike the simpler examples discussed earlier, the forces driving the OO still remain a puzzle.In this letter, we report a unique tetramer OO state in spinel oxide MnTi 2 O 4 (which contains octahedrally-coordi...

show abstract

supporting

confidence: 86%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation