Role of octahedral tilting induced acoustic softening on limiting thermal transport in SrSnO3

Fuente: arXiv
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Main Authors: Hao, Yuzhou, Lookman, Turab, Ding, Xiangdong, Sun, Jun, Gao, Zhibin
Format: Preprint
Published: 2026
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_version_ 1866915812892213248
author Hao, Yuzhou
Lookman, Turab
Ding, Xiangdong
Sun, Jun
Gao, Zhibin
author_facet Hao, Yuzhou
Lookman, Turab
Ding, Xiangdong
Sun, Jun
Gao, Zhibin
contents Octahedral tilting is a fundamental structural distortion in perovskites, governing key phenomena such as lattice stabilizing, soft phonon dynamics, group-theoretical analysis, phase transitions, ferroelectricity, and even for tunable electronic band gap. However, its influence on lattice thermal conductivity (kL) remains poorly understood. In the archetypal perovskite SrTiO3, tilting in the low-temperature tetragonal phase is known to enhance kL by suppressing specific phonon scattering channels around 200 cm-1. Here, we investigate the thermal transport in strontium stannate (SrSnO3), another perovskite oxide that undergoes temperature-driven phase transitions, and reveal a completely opposite effect. Through a systematic study across its orthorhombic, tetragonal, and cubic phases, we demonstrate that octahedral tilting in the tetragonal phase of SrSnO3 anomalously triggers acoustic phonon softening. This softening manifests as reduced frequencies and group velocities in low-frequency (<3 THz) acoustic modes, creating a large decrease for heat transport, particularly along the c-axis. Consequently, kL is significantly suppressed, decreasing from 7.48 W m-1 K-1 to 6.06 W m-1 K-1 as the tilting angle increases by a mere 1 degree. These findings identify tilting-induced acoustic softening as a pivotal mechanism for limiting and controlling anisotropic thermal transport in SrSnO3, presenting a stark contrast to the established behavior in SrTiO3.
format Preprint
id arxiv_https___arxiv_org_abs_2602_20142
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Role of octahedral tilting induced acoustic softening on limiting thermal transport in SrSnO3
Hao, Yuzhou
Lookman, Turab
Ding, Xiangdong
Sun, Jun
Gao, Zhibin
Materials Science
Octahedral tilting is a fundamental structural distortion in perovskites, governing key phenomena such as lattice stabilizing, soft phonon dynamics, group-theoretical analysis, phase transitions, ferroelectricity, and even for tunable electronic band gap. However, its influence on lattice thermal conductivity (kL) remains poorly understood. In the archetypal perovskite SrTiO3, tilting in the low-temperature tetragonal phase is known to enhance kL by suppressing specific phonon scattering channels around 200 cm-1. Here, we investigate the thermal transport in strontium stannate (SrSnO3), another perovskite oxide that undergoes temperature-driven phase transitions, and reveal a completely opposite effect. Through a systematic study across its orthorhombic, tetragonal, and cubic phases, we demonstrate that octahedral tilting in the tetragonal phase of SrSnO3 anomalously triggers acoustic phonon softening. This softening manifests as reduced frequencies and group velocities in low-frequency (<3 THz) acoustic modes, creating a large decrease for heat transport, particularly along the c-axis. Consequently, kL is significantly suppressed, decreasing from 7.48 W m-1 K-1 to 6.06 W m-1 K-1 as the tilting angle increases by a mere 1 degree. These findings identify tilting-induced acoustic softening as a pivotal mechanism for limiting and controlling anisotropic thermal transport in SrSnO3, presenting a stark contrast to the established behavior in SrTiO3.
title Role of octahedral tilting induced acoustic softening on limiting thermal transport in SrSnO3
topic Materials Science
url https://arxiv.org/abs/2602.20142