Structural stability of CuAl${}_2$O${}_4$ under pressure

Abstract

Structural properties of CuAl${}_2$O${}_4$, which was recently argued to show unusual suppression of the Jahn-Teller distortions by the spin-orbit coupling, are investigated under pressures up to 6 GPa. Analysis of X-ray powder diffraction experiments shows that CuAl${}_2$O${}_4$ gets unstable and decomposes onto CuO and Al${}_2$O${}_3$ at pressures $\sim$ 6 GPa and temperature $\sim$ 1000 K. This finding is complemented by the DFT+U+SOC calculations, which demonstrate that this instability is partially driven by a (relatively) large compressibility of strongly Jahn-Teller distorted CuO.

arXiv comment6 pages, 6 figures, 2 tables

References in corpus (10)

• Kitaev quantum spin liquid - concept and materialization
• Models and Materials for Generalized Kitaev Magnetism
• Orbitally-driven Peierls state in spinels
• Spin singlet formation in MgTi${}_2$O${}_4$: evidence of a helical dimerization pattern
• Orbital physics in transition metal compounds: new trends
• CdV2O4: A rare example of a collinear multiferroic spinel
• The Jahn-Teller effect and spin--orbit coupling: friends or foes?
• Spin glass behavior in frustrated quantum spin system CuAl2O4 with a possible orbital liquid state
• Realization of anisotropic compass model on the diamond lattice of Cu${}^{2+}$ in CuAl${}_2$O${}_4$
• Theoretical evidence of spin-orbital-entangled $J_{\mathbf{eff}}$=1/2 state in the 3$d$ transition metal oxide CuAl${}_2$O${}_4$

Cited by in corpus (1)

• Orbital effects in solids: basics, recent progress and opportunities