Magnetostriction of the Heavy Fermion Antiferromagnet YbAgGe

Abstract

In this study our goal is to find evidence of a quantum phase transition in the heavy fermion antiferromagnet YbAgGe when magnetic fields are directed along its crystallographic c-axis at fixed temperatures. We used a capacitive dilatometer to measure the magnetostriction of this material (magnetostriction characterizes the change in length of an object as a result of a varying applied magnetic field) up to 9T. Our data shows evidence of two magnetic phases in the material. Our measurements, combined with thermal expansion data in the same crystallographic orientation, are summarized in a phase diagram which we discuss.