Pressure-temperature magnetic phase diagram of Au$_4$V investigated by electrical resistivity using Designer Diamond Anvils*

The electrical resistivity of Au$_4$V has been measured up to a pressure of 20~GPa between room temperature and 15~K. These measurements were performed using designer diamonds, which consist of lithographically deposited tungsten micro-leads embedded within a single crystal of diamond. The electrical resistivity of Au$_4$V has a kink in its slope at 45~K under ambient pressure, which is associated with a ferromagnetic transition. Designer diamonds can be used with a diamond anvil cell to track the pressure dependence of this ferromagnetic transition, which is found to increase under the application of pressure.