Large magnetocaloric effect in the frustrated antiferromagnet EuIr2P2

We present a theoretical analysis of the magnetocaloric effect in the frustrated antiferromagnet EuIr2P2. Monte Carlo simulations indicate a large magnetic entropy change dSMmax similar to 5 J kg-1 K-1 at T = 2.45 K for a moderate change in the external magnetic field dB = 1.2 Tesla. The highest value of dSM seems to be associated with the presence of a multicritical point in the magnetic field versus temperature phase diagram (at Bm similar to 1.2 Tesla and Tm similar to 2.2 K) but it persists with similar large values for a broad range of temperatures T <= Tm. Single crystal EuIr2P2 magnetization vs magnetic field experiments allowed us to obtain the magnetocaloric effect for T > 2 K. The results are consistent with the theoretical analysis and show a large magnetocaloric effect for T similar to 2.5 K. Finally, we present a phenomenological Landau functional analysis that provides a simplified description of the phase diagram and of the magnetocaloric effect. Although the magnetic frustration in this system leads to a rich phase diagram, we found no clear indication that it plays a significant role enhancing the magneticaloric effect, other than by reducing the transition temperatures and fields.