People
Bruce Gaulin
I am an experimental condensed matter physicist, working in the general area of scattering studies of exotic ground states in new, mostly magnetic, materials. This means that we (my grad students, postdocs, collaborators and myself) make new materials which we think will have interesting and exotic ground states, and then take these materials to forefront neutron and x-ray scattering facilities in North America and around the world.
We perform scattering experiments on these new materials and then work either independently or with our friends in theory to interpret the experiments, and thereby shed light on the exotic properties of the new materials. At present we have three themes to our work; geometrically frustrated magnets, quantum magnets with singlet ground states, and high temperature superconductors. You can read more about our focus on these topics in this introduction.
Katharina Fritsch
Katharina's research involves neutron and x-ray scattering studies on both frustrated and un-frustrated magnetic materials. Her thesis work is mainly concerned with the investigation of the magnetism in cobalt vanadate, a material whose magnetic ions form a buckled version of the flat kagome lattice - a so-called kagome staircase structure. In particular, she's studying the effects of site-disorder and the influence of a transverse magnetic field on the magnetic phase diagram in this material, using neutron scattering techniques.
Katharina also works on frustrated pyrochlores with Kate, as well as quantum magnets that form singlet ground states at low temperatures.
Jerod Wagman
Jerod's research focuses on quantum magnetism in high temperature superconductors. The goal of this research is to use inelastic neutron scattering to understand how the introduction of holes affects the magnetic excitations in these systems. His doctoral thesis is concerned with investigating the rich structure which develops in the material La(2-x)Ba(x)CuO(4) at the intersections of the dispersions of two dimensional incommensurate spin excitations with the different phonons in this material.
His master's thesis was on the related topics of magnetic structure and low lying spin excitations in lightly doped La(2-x)Ba(x)CuO(4).
Dalini Maharaj
Dalini's primary research interests are based on neutron and X-ray scattering studies on frustrated systems which exhibit a variety of exotic behaviour. Her research interests are not limited to frustrated systems as some of her recent work with colleague Katharina, involved a study of the family of chromates, which form spin dimer systems and their low lying spin wave excitations and the effect of disorder. Currently, she is conducting X-ray studies studies along with her colleague Edwin, on an organic spin liquid compound, k-(BEDT-TTF)2Cu2(CN)3. In the future she will be involved in work involving the pyrochlores, specifically stuffed Tb2+xTi2-xO7+y to investigate the effect of stuffing on their physical properties.
Jimin Zhang
Jimin's MSc research is focused on neutron scattering studies on frustrated magnetic pyrochlores. His upcoming MSc. thesis work will be mainly concerned with the doping dependence of magnetism in Tb2Ti(2-x)Sn(x)O7 at low temperatures. The goal is to understand the phase behavior, low energy spin dynamics in these materials.
Additionally, Jimin also works on the crystal field calculations on Tb2Ti2O7 and Tb2Sn2O7 to probe the crystal field energy levels and understand the nature the moment size and anisotropy in these materials.
Edwin Kermarrec
Edwin's research is focused on geometrically frustrated magnetic systems, where new exotic quantum states can exist at very low temperature. He is in particular interested in tracking the quantum spin liquid state by using inelastic neutron scattering technique.
He performed his doctoral work at Université Paris Sud, with Philippe Mendels and Fabrice Bert, where he mainly used NMR and muSR local probes techniques to investigate low dimensional Kagomé magnets.
Makoto Tachibana
Makoto is on sabbatical from the National Institute for Materials Science, Tsukuba, Japan, where he has worked on crystal growth and physical property measurements of transition metal oxides. He will be working with us for a total of two years.
Makoto's research involves x-ray scattering studies of structural phase transitions in various materials. He is particularly interested in the pyrochlore Cd2Nb2O7 and the perovskite system Pr1-xLaxAlO3, both of which show a sequence of unusual and fascinating structural transitions. He is also working on iron pnictide crystals that showsimultaneous magnetic and structural transitions.
Casey Marjerrison
Casey is a senior undergraduate researcher focusing on the materials preparation, crystal growth, characterization and neutron scattering of new magnetic materials. Some of her recent work includes the synthesis and characterization of double perovskite magnetic materials which can be thought of in terms of antiferromagnetically-coupled spins on a face centred cubic (FCC) lattice.
Additionally, she has been investigating the effect of the vanadium oxidation state on the structure and properties of the lutetium vanadate series LuVO3, LuV4O8, Lu2V2O7 and LuVO4.
Miles Couchman
Miles is an undergraduate student involved in the crystal growth and preliminary characterization of exotic magnetic materials. His current focus is on the pyrochlore system Tb(2+x)Ti(2-x)O7 that shows no long-range magnetic order down to 50mK. By growing single crystals of this material with slightly different concentrations of Tb and examining their magnetic properties at low temperatures, he hopes to better understand the ground state of this system.
In the past, Miles has also studied the magnetically frustrated material LuCoGaO4, specifically looking at how doping it with additional magnetic Co2+ ions affects the degree of frustration in the system.
Alan Morningstar
Alan is a summer research assistant performing the preparation, growth, and characterization of single crystals of magnetically frustrated materials. Current focuses are the stuffed spin liquid pyrochlore Tb(2+x)Ti(2-x)O7 and the quantum spin ice pyrochlore Yb2Ti2O7. Strong sample dependence in these materials have been observed thus creating a need for the highest quality single crystals possible. Alan has also been working on the growth of the frustrated system LuGaCuO4, and he's been busy with preliminary characterization of these materials with X-Ray powder diffraction, single crystal Laue diffraction as well as magnetic susceptibility measurements.
Alumni
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