Shuntai Xie

Date of Award


Degree Type


Degree Name

Master of Science




Dr.Yang Song


Pressure-induced structural transformations of two potential hydrogen storage materials, i.e., ammonia borane (NH3-BH3) and calcium borohydride [Ca(BH4)2] were investigated in diamond anvil cells by Raman and IR spectroscopy at ambient temperature up to 14 GPa and 10 GPa, respectively. By monitoring the profile evolutions of Raman and IR modes as well as changes of pressure coefficients, ammonia borane and calcium borohydride were found to undergo several phase transitions upon compression. Decompression measurements suggest those pressure-induced phase transitions were reversible for both materials. Structures of the new phases at different pressure ranges were analyzed based on our Raman and IR data. Our work on ammonia borane complements previous high pressure study on this material by providing new information on the structures and stabilities, while that on calcium borohydride constitutes the first high-pressure experimental study.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.