Structural Phase Transitions of Mg(BH4)2 under Pressure

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Journal of Physical Chemistry C

DOI:https://doi.org/10.1021/jp807842t· OSTI ID:980529

George, L; Drozd, V; Saxena, S; Bardaji, E; Fichtner, M

The structural stability of Mg(BH4)2, a promising hydrogen storage material, under pressure has been investigated in a diamond anvil cell up to 22 GPa with combined synchrotron X-ray diffraction and Raman spectroscopy. The analyses show a structural phase transition around 2.5 GPa and again around 14.4 GPa. An ambient-pressure phase of Mg(BH4)2 has a hexagonal structure (space group P61, a = 10.047(3) A, c = 36.34(1) A, and V = 3176(1) A3 at 0.2 GPa), which agrees well with early reports. The structure of high-pressure phase is found to be different from reported theoretical predictions; it also does not match the high-temperature phase. The high-pressure polymorph of Mg(BH4)2 is found to be stable on decompression, similar to the case of the high-temperature phase. Raman spectroscopic study shows a similarity in high-pressure behavior of as-prepared Mg(BH4)2 and its high-temperature phase.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 980529
• Report Number(s): BNL--93447-2010-JA
• Journal Information: Journal of Physical Chemistry C, Journal Name: Journal of Physical Chemistry C Vol. 113; ISSN 1932-7447
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
43 PARTICLE ACCELERATORS
BEHAVIOR
DIAMONDS
HYDROGEN STORAGE
PRESSURE RANGE MEGA PA 10-100
RAMAN SPECTROSCOPY
SPACE
STABILITY
SYNCHROTRONS
TEMPERATURE RANGE 0400-1000 K
WELLS
X-RAY DIFFRACTION
national synchrotron light source