title: Novel broken symmetry phase from N(2)O at high pressures and high temperatures.
abstract: Simple molecular solids become unstable at high pressures, typically transforming to dense framework and/or metallic structures. We report formation of an unusual ionic solid NO(+)NO(3)(-) (nitrosonium nitrate) from N(2)O at pressures above 20 GPa and temperatures above 1000 K. Synchrotron x-ray diffraction indicates that the compound crystallizes with a structure related to the aragonite form of CaCO(3) and NaNO(3). Raman and infrared spectroscopic data indicate that the structure is noncentrosymmetric and exhibits a strong pressure dependent charge transfer and orientational order.
authors.affiliation: Geophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington, D.C. 20015, USA.
authors.forename: M
authors.initials: M
authors.lastname: Somayazulu
authors.forename: A
authors.initials: A
authors.lastname: Madduri
authors.forename: A F
authors.initials: AF
authors.lastname: Goncharov
authors.forename: O
authors.initials: O
authors.lastname: Tschauner
authors.forename: P F
authors.initials: PF
authors.lastname: McMillan
authors.forename: H K
authors.initials: HK
authors.lastname: Mao
authors.forename: R J
authors.initials: RJ
authors.lastname: Hemley