High-pressure X-ray diffraction study of SrMoO{sub 4} and pressure-induced structural changes

Journal Article · Fri Feb 15 04:00:00 EST 2008 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2007.12.010· OSTI ID:21043899

Errandonea, Daniel ^[1]; Kumar, Ravhi S ^[2]; Xinghua, Ma; Chaoyang, Tu ^[3]

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1. MALTA Consolider Team-Departamento de Fisica Aplicada-ICMUV, Universitat de Valencia, Edificio de Investigacion, c/Dr. Moliner 50, 46100 Burjassot, Valencia (Spain)
2. Department of Physics and Astronomy, High Pressure Science and Engineering Center, University of Nevada, 4505 Maryland Parkway, Las Vegas, NV 89154-4002 (United States)
3. Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

SrMoO{sub 4} was studied under compression up to 25 GPa by angle-dispersive X-ray diffraction. A phase transition was observed from the scheelite-structured ambient phase (space group I4{sub 1}/a) to a monoclinic fergusonite phase (space group I2/a) at 12.2(9) GPa. The unit-cell parameters of the high-pressure phase are a=5.265(9) A, b=11.191(9) A, c=5.195 (5) A, and {beta}=90.9(1){sup o}, Z=4 at 13.1 GPa. There is no significant volume collapse at the phase transition. No additional phase transitions were observed and on release of pressure the initial phase is recovered, implying that the observed structural modifications are reversible. The reported transition appeared to be a ferroelastic second-order transformation producing a structure that is a monoclinic distortion of the low-pressure phase and was previously observed in compounds isostructural to SrMoO{sub 4}. A possible mechanism for the transition is proposed and its character is discussed in terms of the present data and the Landau theory. Finally, the room temperature equation of states is reported and the anisotropic compressibility of the studied crystal is discussed in terms of the compression of the Sr-O and Mo-O bonds. - Graphical abstract: The evolution of the structure of SrMoO{sub 4} upon compression was established using synchrotron X-ray diffraction and a diamond-anvil cell. A pressure-induced phase transition was found involving a symmetry decrease from tetragonal to monoclinic. A transition mechanism is proposed and its ferroelastic character is discussed in terms of the Landau theory.

• OSTI ID: 21043899
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 181; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
COMPRESSIBILITY
COMPRESSION
EQUATIONS OF STATE
MOLYBDATES
MONOCLINIC LATTICES
PHASE TRANSFORMATIONS
PRESSURE RANGE GIGA PA
SPACE GROUPS
STRONTIUM COMPOUNDS
SYMMETRY
SYNCHROTRONS
TEMPERATURE RANGE 0273-0400 K
TETRAGONAL LATTICES
X-RAY DIFFRACTION