Dr. Takahiro Matsuoka

Mandrus Group, Materials Science and Engineering, Institute for Advanced Materials and Manufacturing, The University of Tennessee, Knoxville

Quantum materials have been fascinating us with their rich emergent phenomena. It is important to be able to perturb the materials to study their response. A chemical substitution is a powerful tool, but it increases the disorder in a material. The application of a magnetic field is very clean and widely used. Strain and pressure can also be used to tune materials, but these are much less common due to the technical barriers in electrical and thermal transport measurements, which are essential in quantum systems studies. We have developed the capability to perform the transport measurements under applied pressure while sweeping the magnetic field and changing temperature (Fig. 1). Using diamond anvil cells (DACs) combined with a Physical Property Measurement System (PPMS, Quantum Design), electrical transport measurements up to 50 GPa in the magnetic field to 9 T and temperature from 1.7 to 350 K are possible. We are applying the techniques to the studies of magnetic materials.

In this talk, the electrical transport and structural properties of NiPS3 will be discussed. NiPS3 is a van der Walls magnetic compound and attracts interest in pursuing their wider applications to spintronics devices utilizing optical, electronic, and magnetic tunability. We combined the electrical transport measurements with XRD and observed a pressure-induced insulator-to-metal transition (IMT) accompanied by a structural transformation at 30 GPa. Comparing the results reported for different pressure conditions, the IMT is found to occur at different pressures depending on the pressure condition, indicating the material is highly sensitive to strain conditions. It may enable a physical property tuning by strain application.