Title: Possible spin gapless semiconductor type behaviour in CoFeMnSi epitaxial thin films,
Abstract: Spin-gapless semiconductors with their unique band structures have recently
attracted much attention due to their interesting transport properties that can
be utilized in spintronics applications. We have successfully deposited the
thin films of quaternary spin-gapless semiconductor CoFeMnSi Heusler alloy on
MgO (001) substrates using a pulsed laser deposition system. These films show
epitaxial growth along (001) direction and display uniform and smooth
crystalline surface. The magnetic properties reveal that the film is
ferromagnetically soft along the in-plane direction and its Curie temperature
is well above 400 K. The electrical conductivity of the film is low and
exhibits a nearly temperature independent semiconducting behaviour. The
estimated temperature coefficient of resistivity for the film is -7x10^-10
Ohm.m/K, which is comparable to the values reported for spin-gapless
semiconductors.