Predictions of thermal expansion coefficients of rare-earth zirconate pyrochlores: A quasi-harmonic approximation based on stable phonon modes

2016 ◽  
Vol 119 (23) ◽  
pp. 235103 ◽  
Author(s):  
Guoqiang Lan ◽  
Bin Ouyang ◽  
Yushuai Xu ◽  
Jun Song ◽  
Yong Jiang
Keyword(s):  
Thermal Expansion ◽  
Rare Earth ◽  
Harmonic Approximation ◽  
Phonon Modes ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

Experimental analysis of overall thermal properties of Nd:La2CaB10O19crystals

2012 ◽  
Vol 45 (6) ◽  
pp. 1182-1186 ◽  
Author(s):  
Jianxiu Zhang ◽  
Yang Wu ◽  
Guochun Zhang ◽  
Yin Li ◽  
Yicheng Wu
Keyword(s):  
Thermal Expansion ◽  
Rare Earth ◽  
Frequency Conversion ◽  
Frequency Doubling ◽  
Nonlinear Frequency ◽  
Rare Earth Ion ◽  
Nonlinear Frequency Conversion ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Measured Specific Heat

Pure or rare-earth-ion-doped La2CaB10O19(LCB) is a promising optical material for nonlinear frequency conversion, laser and self-frequency doubling applications. In this paper, the thermophysical properties of Nd3+-doped LCB (Nd:LCB) crystals were measured and compared with those of pure and of Yb3+- and Er3+-doped LCB, as well as other borate nonlinear optical crystals. The melting points of rare-earth-doped LCB crystals are lower than that of pure LCB. Thermal expansion coefficients along thea,b,c,c*,a*, 〈110〉 and 〈110〉* directions have been measured, and the principal expansion coefficients were calculated to be 1.85 × 10−6, 4.13 × 10−6and 8.79 × 10−6 K−1. The measured specific heat of Nd:LCB is lower than that of pure LCB, resulting in a larger internal temperature gradient under irradiation by a pulsed laser beam. The measured thermal expansion anisotropy of Nd:LCB is stronger than that of pure LCB. The thermal conductivities of Nd:LCB along thecandc* directions are smaller than those along other crystallographic directions.

Thermal expansion of the new perovskite substrates DyScO3 and GdScO3

2005 ◽  
Vol 20 (4) ◽  
pp. 952-958 ◽  
Author(s):  
M.D. Biegalski ◽  
J.H. Haeni ◽  
S. Trolier-McKinstry ◽  
D.G. Schlom ◽  
C.D. Brandle ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Rare Earth ◽  
Lattice Spacing ◽  
Epitaxial Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Increasing Temperature

The thermal expansion coefficients of DyScO3 and GdScO3 were determined from298 to 1273 K using x-ray diffraction. The average thermal expansion coefficients of DyScO3 and GdScO3 were 8.4 and 10.9 ppm/K, respectively. No phase transitions were detected over this range, though the orthorhombicity decreased with increasing temperature. These thermal expansion coefficients are similar to other oxide perovskites (e.g., BaTiO3 or SrTiO3), making these rare-earth scandates promising substrates for the growth of epitaxial thin films of many oxide perovskites that have similar lattice spacing and thermal expansion coefficients.

Commentary on “Constraints on the Equations of State of stiff anisotropic minerals: rutile, and the implications for rutile elastic barometry” [Miner. Mag. 83 (2019) pp. 339–347]

2020 ◽  
Vol 84 (2) ◽  
pp. 355-357
Author(s):  
Ross J. Angel ◽  
Matteo Alvaro ◽  
Peter Schmid-Beurmann ◽  
Herbert Kroll
Keyword(s):  
Thermal Expansion ◽  
Equation Of State ◽  
Equations Of State ◽  
Harmonic Approximation ◽  
Thermal Pressure ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

AbstractThe conclusion of Zaffiro et al. (2019; Constraints on the Equations of State of stiff anisotropic minerals: rutile, and the implications for rutile elastic barometry. Mineralogical Magazine, 83, 339–347) that the Mie–Grüneisen–Debye (MGD) Equation of State (EoS) cannot fit the available data for rutile is shown to be incorrect, even though rutile exhibits significant anisotropic thermal pressure which invalidates the quasi-harmonic approximation used as the basis for the MGD EoS. The refined parameters for the MGD EoS of rutile are: KTR0= 205.05(25) GPa, $K_{TR0}^{\prime} $ = 7.2(5), θD = 399(20) K, γ0= 1.40(2) and q = 1.5(7). This EoS predicts volumes, bulk moduli and volume thermal expansion coefficients for rutile at metamorphic conditions that are statistically indistinguishable from those predicted by the ‘isothermal’ type of EoS reported previously.

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