Regulation of thermal transport via ferroic interfaces

Supporting second-principle simulations of the thermal transport properties of individual domain walls suggested that a higher volume proportion of domain wall material would be required to resolve their cumulative effect in our measurements.For local imaging of thermal properties using SThM, a very sharp, temperature-sensitive probe, is used to collect spatially resolved temperature maps of the LaAlO3 samples under an imposed thermal gradient.

Steps in temperature across domain walls were expected due to their thermal boundary resistance, however, these features could not be resolved in the experimentally obtained temperature maps due to challenges in stabilising large enough thermal gradients. In response to this, a micropatterned heater and sample geometry is explored with a view to maximising the achievable thermal gradient. Finite element modelling suggests that three orders of magnitude increase in the thermal gradient can be achieved, compared to the macroscopic geometry<br><br><i>Thesis embargoed until 31st December 2027 </i>