Synthesis, structural and physical characterisation of lacunar spinels hosting Neel-type skyrmions

Skyrmions are topologically protected spin texture occurring when a
balanced competition between ferromagnetic and antisymmetric
exchange interactions is present in a magnetic material and therefore
require that both time reversal and spatial symmetry are broken. This
PhD will investigate the possible emergence of a skyrmion phase in
the polar magnetic phases GaMo4X8 (X=S;Se) motivated by recent
experimental and theoretical work in this family of materials. To
achieve the student will synthesise polycrystalline powders and single
crystals of these compounds and carry out a detailed structural and
magnetic study. This will involve powder and single crystal neutron
scattering methods such as polarised neutron analysis and small
angle neutron scattering measurements. The magnetic phase
diagram established by these various measurement methods will be
compared with Monte Carlo simulation of a classical spin Heisenberg
allowing us to understand the impact of physical parameters such as
spin-orbit coupling on the stability and size of skyrmions in bulk
crystals