Crystal structure of LaTiO_3.41 under pressure

TL;DR

This study investigates the crystal structure of LaTiO_3.41 under high pressure, revealing stability up to 18 GPa, a reversible phase transition between 18-24 GPa, and anisotropic compressibility, with implications for its electronic properties.

Contribution

The paper provides the first detailed high-pressure structural analysis of LaTiO_3.41, identifying phase stability, transition behavior, and anisotropic compression characteristics.

Findings

Stable phase up to 18 GPa

Reversible phase transition at 18-24 GPa

Anisotropic axis compressibilities (1:2:3 ratio)

Abstract

The crystal structure of the layered, perovskite-related LaTiO_3.41 (La_5Ti_5O_{17+\delta}) has been studied by synchrotron powder x-ray diffraction under hydrostatic pressure up to 27 GPa (T = 295 K). The ambient-pressure phase was found to remain stable up to 18 GPa. A sluggish, but reversible phase transition occurs in the range 18--24 GPa. The structural changes of the low-pressure phase are characterized by a pronounced anisotropy in the axis compressibilities, which are at a ratio of approximately 1:2:3 for the a, b, and c axes. Possible effects of pressure on the electronic properties of LaTiO_3.41 are discussed.