Intrinsic Thermal Shock Behavior of Common Rutile Oxides

Denis Music,Bastian Stelzer

doi:10.3390/physics1020022

Abstract

Rutile TiO2, VO2, CrO2, MnO2, NbO2, RuO2, RhO2, TaO2, OsO2, IrO2, SnO2, PbO2, SiO2, and GeO2 (space group P42/mnm) were explored for thermal shock resistance applications using density functional theory in conjunction with acoustic phonon models. Four relevant thermomechanical properties were calculated, namely thermal conductivity, Poisson’s ratio, the linear coefficient of thermal expansion, and elastic modulus. The thermal conductivity exhibited a parabolic relationship with the linear coefficient of thermal expansion and the extremes were delineated by SiO2 (the smallest linear coefficient of thermal expansion and the largest thermal conductivity) and PbO2 (vice versa). It is suggested that stronger bonding in SiO2 than PbO2 is responsible for such behavior. This also gave rise to the largest elastic modulus of SiO2 in this group of rutile oxides. Finally, the intrinsic thermal shock resistance was the largest for SiO2, exceeding some of the competitive phases such as Al2O3 and nanolaminated Ti3SiC2.

Highlights

Rutile oxides, including TiO2, VO2, CrO2, MnO2, NbO2, RuO2, RhO2, TaO2, OsO2, IrO2, SnO2, PbO2, SiO2, and GeO2, are very common oxides and broadly explored due to their interesting properties [1,2]
VO2 undergoes the Mott transition at a low temperature of 68 ◦ C [8], which is relevant for some applications such as smart windows
Density functional theory [17] was employed in the current work to calculate κ, ν, α, and Y for

Summary

Introduction

Rutile oxides (space group P42 /mnm, prototype TiO2 ), including TiO2 , VO2 , CrO2 , MnO2 , NbO2 , RuO2 , RhO2 , TaO2 , OsO2 , IrO2 , SnO2 , PbO2 , SiO2 , and GeO2 , are very common oxides and broadly explored due to their interesting properties [1,2]. NbO2 exhibits the highest known Mott transition temperature of approximately 800 ◦ C [5,6,7]. VO2 undergoes the Mott transition at a low temperature of 68 ◦ C [8], which is relevant for some applications such as smart windows. SiO2 , in its various forms, is known for high thermal shock resistance [9]. Oxides are refractory solids [10,11], but still many of their high-temperature properties are either unknown or not systematically explored. One of these is thermal shock behavior

Methods

Results

Conclusion