| Full text | |
| Author(s): |
Samanta, K.
;
Tartaglia, R.
;
Kaneko, U. F.
;
Souza-Neto, N. M.
;
Granado, E.
Total Authors: 5
|
| Document type: | Journal article |
| Source: | PHYSICAL REVIEW B; v. 101, n. 7, p. 6-pg., 2020-02-18. |
| Abstract | |
The crystal lattice of Sr2IrO4 is investigated with synchrotron x-ray powder diffraction under hydrostatic pressures up to P = 43 GPa and temperatures down to 20 K. The tetragonal unit cell is maintained over the whole investigated pressure range, within our resolution and sensitivity. The c-axis compressibility kappa(c)(P, T) -(1/c)(dc/dP) presents an anomaly with pressure at P-1 = 17 GPa at fixed T = 20 K that is not observed at T = 300 K, whereas kappa(a)(P, T) is nearly temperature independent and shows a linear behavior with P. The anomaly in kappa(c)(P, T) is associated with the onset of long-range magnetic order, as evidenced by an analysis of the temperature dependence of the lattice parameters at fixed P = 13.7 +/- 0.5 GPa. At fixed T = 20 K, the tetragonal elongation c/a(P, T) shows a gradual increment with pressure and a depletion above P-2 = 30 GPa that indicates an orbital transition and possibly marks the collapse of the J(eff) = 1/2 spin-orbit-entangled state. Our results support pressure-induced phase transitions or crossovers between electronic ground states that are sensed, and therefore can be probed, by the crystal lattice at low temperatures in this prototype spin-orbit Mott insulator. (AU) | |
| FAPESP's process: | 17/10581-1 - Emergent phenomena in reduced dimension systems |
| Grantee: | Pascoal Jose Giglio Pagliuso |
| Support Opportunities: | Special Projects |
| FAPESP's process: | 18/20142-8 - Vibrational dynamics, spin waves and orbital excitations in transition-metal oxides |
| Grantee: | Eduardo Granado Monteiro da Silva |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 16/00756-6 - Synthesis and Fundamental Investigation of Novel Correlated Electron Systems with Strong Spin-orbit Coupling |
| Grantee: | Kousik Samanta |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |