The fabrication and application of novel materials devices requires an intensive understanding of material properties under varying

The fabrication and application of novel materials
devices requires an intensive understanding of
material properties under varying conditions of
fabrication and application.  It is with this in mind
that the materials characterization laboratory
performs the duties of material study.  The goal of
the research performed at MaChaLa is to characterize
HTS, LTS, and CMR materials to elucidate intrinsic
material properties for the refinement of materials
fabrication and manipulation.

VTSLM Experimental Setup


The materials studied at MaChaLa all have novel
temperature dependent resistivities.  These materials
possess unusual temperature dependent resistive
transitions.  These transitions can be exploited by
VTSLM.  The VTSLM method uses a modulated laser beam
as a local heat source incident approximately
orthogonal to the plane of the film surface.  The film
is cooled to the critical temperature regime and is
biased with a DC current.  The local heating will
provoke an AC voltage response. This voltage response is
modulated according to the modulated frequency of the
laser source.  A Lock-In Amplifier and Pre-Amplifier
then measure the signal.  This scanning is performed
in the transition region and controlled remotely by
laboratory automation software we have written in the
G programming language.   These scans are performed in
the transition region, so that we may observe the
functional dependence of temperature on AC voltage response.

Sample VTSLM image