Thermal Properties of Magnesium Hydroxide Using First-Principles Method

Abstract:

The thermal properties of the magnesium hydroxide crystalline powder samples, which were prepared by us, were investigated by first-principles method. The calculated results show that the forbidden band of phonon appears in both 14～19 THz and 33～102 THz. There are 3 acoustic lattice wave branches and 12 optical ones, where two horizontal acoustic branches are degeneracy and two horizontal optical ones are degeneracyhe. Moreover, The constant-volume specific heat quickly increases at low temperature; but it tends to be flat at high temperature. Besides, the Debye temperature quickly increases to 483K from temperature 0K to 10K; but from temperature 100K to 1000K, it is linear with temperature approximately, whose increasing rate is about 1.333; at temperature of 1000K, the Debye temperature is 1930K, reaching its maximum.

• Periodical: Key Engineering Materials (Volumes 512-515)
• Pages: 609-612
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.512-515.609
• Online since: June 2012
• Authors: Qing Li Ren, Qiang Luo
• Keywords: First-Principles Method, Magnesium Hydroxide, Thermal Property

References

[1] M. Catti, G. Ferraris, S. Hull, A. Pavese, Static compression and H disorder in brucite, Mg(OH)2, to 11 GPa: a powder neutron diffraction study, Phys Chem Miner. 22 (1995) 200-206.

DOI: 10.1007/bf00202300

[2] Y. Xiong, Thermodynamic properties of brucite determined by solubility studies and their significance to nuclear waste isolation, Aquat Geochem. 14 (2008) 223-238.

DOI: 10.1007/s10498-008-9034-3

[3] J. Horita, A. M. Santos, C. A. Tulk, B. C. Chakoumakos, V. B. Polyakov, High-pressure neutron diffraction study on H-D isotope effects in brucite, Phys Chem Minerals. 37 (2010) 741-749.

DOI: 10.1007/s00269-010-0372-5

[4] A. N. Belevtsev, S. A. Baikova, V. I. Zhavoronkova, N. N. Mel'nikova, and V. I. Nosenko, Effectiveness of aquamag ground brucite in water treatment processes, Metallurgist. 51 (2007) 295-297.

DOI: 10.1007/s11015-007-0055-8

[5] G. W. Brindley, G. J. Ogilvie, The texture of single crystals of brucite, Acta Cryst. 5(1952) 412-413

DOI: 10.1107/s0365110x5200126x

[6] A. P. Shpak, E. A. Kalinichenko, A. S. Lytovchenko, I. A. Kalinichenko, G. V. Legkova, N. N. Bagmut, The effect of c-irradiation on the structure and subsequent thermal decomposition of brucite, Phys Chem Minerals. 30 (2003) 59-68.

DOI: 10.1007/s00269-002-0290-2

[7] D. D. Elleman, D. Williams, Proton positions in brucite crystals, J Chem Phys. 25 (1956) 742-744.

DOI: 10.1063/1.1743040

[8] M. Catti, G. Ferraris, S. Hull, A. Pavese, Static compression and H disorder in brucite, Mg(OH)2, to 11 GPa: a powder neutron diffraction study, Phys Chem Miner. 22 (1995) 200-206.

DOI: 10.1007/bf00202300

[9] J. J. Xiong, Design of Materials, first ed., Press of Tianjing University, Tianjing, 2000.

[10] J. A. White, D. M. Bird, Implementation of gradient-corrected exchange-correlation potentials in Car-Parrinello total-energy calculations, Phys Rev B. 50 (1994) 4954-4957.

DOI: 10.1103/physrevb.50.4954

[11] Q. L. Ren, B. Liu, S. T. Chen, Mechanism of grain growth about Mg(OH)2 under thermal liquid condition, Rare Metal Materials Science and Engineering. (2004) 1-4.