Scholarlink

<p>The equation of state of ilmenite (FeTiO<sub>3</sub>) and geikielite (MgTiO<sub>3</sub>) have been investigated using in situ synchrotron X-ray diffraction at high pressures up to ~ 21.8 GPa and ~ 23.0 GPa, respectively. No phase transitions were observed within the experimental pressure ranges for both samples. The pressure-volume data were fitted using the third-order Birch-Murnaghan equation of state (EoS), yielding the following results: for FeTiO<sub>3</sub>, the zero-pressure unit-cell volume <i>V</i><sub>0</sub> = 312.2(1) Å<sup>3</sup>, the zero-pressure bulk modulus <i>K</i><sub>0</sub> = 165(4) GPa, and its pressure derivative <i>K</i>′<sub>0</sub> = 6.6(6); for MgTiO<sub>3</sub>, <i>V</i><sub>0</sub> = 304.17(8) Å<sup>3</sup>, <i>K</i><sub>0</sub> = 157(3) GPa, and <i>K</i>′<sub>0</sub> = 7.3(4). Additionally, the axial compressional behavior of FeTiO<sub>3</sub> and MgTiO<sub>3</sub> were also fitted with a linearized third-order Birch-Murnaghan EoS. The axial compressibility coefficients for FeTiO<sub>3</sub> along the <i>a-</i> and <i>c-</i>axes are <i>β</i><sub><i>a</i></sub> = 1.43(4) × 10<sup>− 3</sup> GPa<sup>-1</sup> and <i>β</i><sub><i>c</i></sub> = 3.17(11) × 10<sup>− 3</sup> GPa<sup>-1</sup>, respectively, with an anisotropic ratio of <i>β</i><sub><i>a</i></sub>: <i>β</i><sub><i>c</i></sub> = 0.45: 1.00, while <i>β</i><sub><i>a</i></sub> = 1.76 (7) × 10<sup>− 3</sup> GPa<sup>-1</sup> and <i>β</i><sub><i>c</i></sub> = 2.61(7) × 10<sup>− 3</sup> GPa<sup>-1</sup> with an anisotropic ratio of <i>β</i><sub><i>a</i></sub>: <i>β</i><sub><i>c</i></sub> = 0.67: 1.00 for MgTiO<sub>3</sub>. Both FeTiO<sub>3</sub> and MgTiO<sub>3</sub> exhibit the axial compression anisotropy, of which FeTiO<sub>3</sub> shows stronger axial compressibility anisotropy than MgTiO<sub>3</sub>. Moreover, the potential influencing factors (e.g., cation radius, crystal structure, and chemical bond strength) on the bulk moduli and the anisotropic linear compressibilities of FeTiO<sub>3</sub> and MgTiO<sub>3</sub> were further discussed.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Equation of state of FeTiO3 and MgTiO3 by in-situ synchrotron X-ray diffraction at high pressures

  • 期刊论文

  • 发表日期：

    2025年7月7日

查看全文
  • Kai Wang,
  • Jingui Xu,
  • Shanrong Zhang,
  • Qifa Zhong,
  • Wei Zhao,
  • Dawei Fan

摘要

The equation of state of ilmenite (FeTiO3) and geikielite (MgTiO3) have been investigated using in situ synchrotron X-ray diffraction at high pressures up to ~ 21.8 GPa and ~ 23.0 GPa, respectively. No phase transitions were observed within the experimental pressure ranges for both samples. The pressure-volume data were fitted using the third-order Birch-Murnaghan equation of state (EoS), yielding the following results: for FeTiO3, the zero-pressure unit-cell volume V0 = 312.2(1) Å3, the zero-pressure bulk modulus K0 = 165(4) GPa, and its pressure derivative K′0 = 6.6(6); for MgTiO3, V0 = 304.17(8) Å3, K0 = 157(3) GPa, and K′0 = 7.3(4). Additionally, the axial compressional behavior of FeTiO3 and MgTiO3 were also fitted with a linearized third-order Birch-Murnaghan EoS. The axial compressibility coefficients for FeTiO3 along the a- and c-axes are βa = 1.43(4) × 10− 3 GPa-1 and βc = 3.17(11) × 10− 3 GPa-1, respectively, with an anisotropic ratio of βa: βc = 0.45: 1.00, while βa = 1.76 (7) × 10− 3 GPa-1 and βc = 2.61(7) × 10− 3 GPa-1 with an anisotropic ratio of βa: βc = 0.67: 1.00 for MgTiO3. Both FeTiO3 and MgTiO3 exhibit the axial compression anisotropy, of which FeTiO3 shows stronger axial compressibility anisotropy than MgTiO3. Moreover, the potential influencing factors (e.g., cation radius, crystal structure, and chemical bond strength) on the bulk moduli and the anisotropic linear compressibilities of FeTiO3 and MgTiO3 were further discussed.