Effects of cation substitution and order-disorder on P-V-T equations of state of cubic spinels

Geophysical Laboratory and Center for High-Pressure Research, Washington, DC, United States

The geometric simplicity of the cubic spinel structure allows prediction of equation-of-state parameters from cation-anion bond distances, bond compressibilities, and bond thermal expansivities, which can be estimated from crystal chemical systematics. We calculate effects of cation substitution and order-disorder reactions for phases of geological interest: MgAl ₂ O ₄ (spinel), MgFe ₂ O ₄ (magnesioferrite), Fe ₃ O ₄ (magnetite), and Mg ₂ SiO ₄ (ringwoodite). Compressibilities for normal vs. inverse variants of A (super 2+) B (super 3+) ₂ O ₄ and A (super 4+) B (super 2+) ₂ O ₄ spinels are predicted to differ by as much as 17%, and thermal expansivities by as much as 15%, as a result of the differential compressibilities or thermal expansivities of divalent, trivalent, and tetravalent cations in tetrahedral vs. octahedral coordination. These effects are unexpectedly large, and they suggest that care must be taken to document the state of cation order before and after any pressure-volume-temperature equation-of-state measurements on phases subject to a range of ordered states.

This record provided courtesy of AGI/GeoRef.

This article has been cited by other articles:

				Y. Kono, A. Miyake, M. Ishikawa, and M. Arima Temperature derivatives of elastic wave velocities in plagioclase (An51{+/-}1) above and below the order-disorder transition temperature American Mineralogist, April 1, 2008; 93(4): 558 - 564. [Abstract] [Full Text] [PDF]

				S. P. Slotznick and S.-H. Shim In situ Raman spectroscopy measurements of MgAl2O4 spinel up to 1400 {degrees}C American Mineralogist, February 1, 2008; 93(2-3): 470 - 476. [Abstract] [Full Text] [PDF]

				F. Nestola, T. B. Ballaran, T. Balic-Zunic, F. Princivalle, L. Secco, and A. Dal Negro Comparative compressibility and structural behavior of spinel MgAl2O4 at high pressures: The independency on the degree of cation order American Mineralogist, November 1, 2007; 92(11-12): 1838 - 1843. [Abstract] [Full Text] [PDF]

				H. Uchida, K. Righter, B. Lavina, M. M. Nowell, S. I. Wright, R. T. Downs, and H. Yang Investigation of synthetic Mg1.3V1.7O4 spinel with MgO inclusions: Case study of a spinel with an apparently occupied interstitial site American Mineralogist, July 1, 2007; 92(7): 1031 - 1037. [Abstract] [Full Text] [PDF]

				L. Li, P. Carrez, and D. Weidner Effect of cation ordering and pressure on spinel elasticity by ab initio simulation American Mineralogist, January 1, 2007; 92(1): 174 - 178. [Abstract] [Full Text] [PDF]

				M. A. Carpenter Elastic properties of minerals and the influence of phase transitions American Mineralogist, February 1, 2006; 91(2-3): 229 - 246. [Abstract] [Full Text] [PDF]

				S. M. Antao, I. Hassan, W. A. Crichton, and J. B. Parise Effects of high pressure and high temperature on cation ordering in magnesioferrite, MgFe2O4, using in situ synchrotron X-ray powder diffraction up to 1430 K and 6 GPa American Mineralogist, October 1, 2005; 90(10): 1500 - 1505. [Abstract] [Full Text] [PDF]

				D. Levy, V. Diella, A. Pavese, M. Dapiaggi, and A. Sani P-V equation of State, thermal expansion, and P-T stability of synthetic zincochromite (ZnCr2O4 spinel) American Mineralogist, July 1, 2005; 90(7): 1157 - 1162. [Abstract] [Full Text] [PDF]

				M. H. Manghnani, G. Amulele, J. R. Smyth, C. M. Holl, G. Chen, V. Prakapenka, and D. J. Frost Equation of state of hydrous Fo90 ringwoodite to 45 GPa by synchrotron powder diffraction Mineralogical Magazine, June 1, 2005; 69(3): 317 - 323. [Abstract] [Full Text] [PDF]

				A. I. Turkin and V. A. Drebushchak Cation distribution in MgFe2O4 vs. pressure and temperature: Experiments in a "piston-cylinder" apparatus American Mineralogist, April 1, 2005; 90(4): 764 - 767. [Abstract] [Full Text] [PDF]

				F. Meducin, S. A.T. Redfern, Y. Le Godec, H. J. Stone, M. G. Tucker, M. T. Dove, and W. G. Marshall Study of cation order-disorder in MgAl2O4 spinel by in situ neutron diffraction up to 1600 K and 3.2 GPa American Mineralogist, July 1, 2004; 89(7): 981 - 986. [Abstract] [Full Text] [PDF]

				M. Yu. Lavrentiev, M. Yu. Lavrentiev, J.A. Purton, and N.L. Allan Ordering in spinels--A Monte Carlo study American Mineralogist, October 1, 2003; 88(10): 1522 - 1531. [Abstract] [Full Text] [PDF]

				A. M. Hofmeister and H.-k. Mao Redefinition of the mode Gruneisen parameter for polyatomic substances and thermodynamic implications PNAS, January 22, 2002; 99(2): 559 - 564. [Abstract] [Full Text] [PDF]

				A.M. Hofmeister and H.K. Mao Evaluation of shear moduli and other properties of silicates with the spinel structure from IR spectroscopy American Mineralogist, May 1, 2001; 86(5-6): 622 - 639. [Abstract] [Full Text] [PDF]