Abstract:

TiOBr belongs to a select group of quasi-one-dimensional quantum materials which undergo a spin-Peierls phase transition.  Driven by a combination of antiferromagnetic interactions and strong magnetoelastic coupling, these compounds develop a dimerized singlet ground state at low temperatures.  However, unlike conventional spin-Peierls compounds such as CuGeO3, TiOBr appears to differ from the standard spin-Peierls model in several important respects.  In particular, TiOBr has been
shown to exhibit not one, but two successive phase transitions upon cooling, displaying both commensurate and incommensurate spin-Peierls
ground states.  In this talk I will discuss the results of recent x-ray and neutron scattering measurements on single crystal and powder
samples of TiOBr.  I will describe how these measurements can provide insight into the nature of the low temperature phase diagram, critical
behaviour, and magnetic excitation spectrum of this unusual material.