Susceptibility measurements at high pressures using a microcoil system in an anvil cell

We present here a microcoil setup for susceptibility measurements in anvil cells. In contrast to previous designs, we have placed the secondary coil inside the high pressure volume. This dramatically boosts the signal and eliminates the need for complex background subtraction. For samples of lead, tin, and the metal–insulator oxide calcium ruthenate (Ca2RuO4), our procedure has produced very clear signals for both superconducting transitions and ferromagnetic ordering with a weak magnetic moment (0.2 μB/Ru), up to 75 kbar, with a signal-to-noise ratio of ∼80.