Malcolm Nicol's Research Interests

My research aims to develop better ways of thinking about materials under extreme conditions: pressures to more than 1 million atmospheres, temperatures to more than 8000 K, and times from 30 psec to the age of the planets. Current activities focus around the UNLV High Pressure Science and Engineering Center (HIPSEC). Besides laboratories on campus, HIPSEC is a leader of the High Pressure Collaborative Access Team (HPCAT) that built and runs a world-class facility for X-ray diffraction and spectroscopy at the Advanced Photon Source of Argonne National Laboratory.

In the past, my group innovated applying Mössbauer and Raman spectra at high pressures and showed that iron is not ferromagnetic under conditions in the Earth's core; froze oxygen at room temperature for the first time, measured its melting curves to 700 K and the melting curve of N₂ to 1000 K; discovered d- and e-O₂; showed the general instability of multiply‑bonded carbon at very high pressures by  studying polymers of CO, C₂N₂, HCN, COCl₂ and alkyl‑ and alkoxy‑ naphthalenes; determined the structures of e-O₂ and polymeric CO₂-V; and built at SSRL the x-ray diffractometer for the UC-National Labs PRT

Recent advances include:    synthesizing cubic-BN and b-Si₃N₄ directly from the elements;discovering the ionic dimer of carbon dioxide, CO⁺⁺CO₃⁼, and solving the structure of this and several other phases of solid CO₂; developing a new pressure measuring system based on Raman spectra of ¹²C and ¹³C diamond; and defining the nature of the cubic-hexagonal closest packed structural transformation of solid xenon. Much of our experimental work is done in collaboration with Prof. Cornelius and Pravica, their groups, other members of the HIPSEC team and scientists at DOE national laboratories. All of them can help to advance a project.

We are working to define better pressure media for high-pressure (million-atmosphere) research, to develop new high-pressure cells, to do micro-absorption spectroscopy on samples of high explosives and other reactive materials, and to synthesize new materials that may be harder than diamond. During this summer, we also want to develop a sapphire-anvil cell that contains samples of millimeter dimensions; that is, at least 200 times the volumes of current cells. Other devices involving SiC anvils might be tested. Both would be valuable for high-pressure spectroscopy, synthesis, and neutron diffraction work.

Another interesting problem for the summer might be to test potential synthetic routes to produce macroscopic quantities of a new, possibly hard, carbon nitride. In addition to work at UNLV, this should involve at least a few days taking X-ray data at HPCAT.

With Prof. Pravica’s group, we are studying the structures and properties of high explosives at high pressures. We recently discovered a new high-pressure phase of PETN and want to define the transition conditions and to characterize it by Raman spectroscopy, X-ray spectroscopy and diffraction. A summer student could establish the phase boundary, analyze the vibrational spectrum of the new phases, and help to solve its structure.