R3: High-pressure science and deep Earth’s material

[R3-07] Determination of thermal expansivity of calcium ferrite-type MgAl₂O₄

*Hiroshi Kojitani¹, Mei Gonai¹, Yoshiyuki Inaguma¹, Masaki Akaogi² (1. Gakushuin Univ., 2. Univ. of Tokyo)

Keywords:calcium ferrite, MgAl2O4, thermal expansivity, high-temperature X-ray diffraction measurement

In this study, calcium ferrite-type MgAl₂O₄ sample was prepared by several high-pressure synthesis runs and its thermal expansivity was determined by performing powder X-ray diffraction measurements in the temperature range of 303-673 K with 50 K interval. When the thermal expansivity was expressed as a linear function of temperature (α = a + bT), thermal expansion coefficients were obtained to be a = 2.46(13)x10^-5 (1/K) and b = 1.2(3)x10^-8 (1/K²) by the least squares fitting of unit cell volume-temperature data.