The magnetic susceptibility, specific heat and dielectric constant of hexagonal YMnO3, LuMnO3and ScMnO3

We report the magnetic susceptibility, specific heat and dielectric constant for high-purity polycrystalline samples of three hexagonal manganites: YMnO 3 , LuMnO 3 and ScMnO 3 . These materials can exhibit a ferroelectric transition at very high temperatures ( T FE >700 K). At lower temperatures there is magnetic ordering of the frustrated Mn 3+ spins ( S = 2) on a triangular Mn lattice (YMnO 3 : T N = 71 K; LuMnO 3 : T N = 90 K and ScMnO 3 : T N = 130 K). The transition is characterized by a sharp kink in the magnetic susceptibility at T N below which it continues to increase due to the frustration on the triangular lattice. The specific heat shows one clear continuous phase transition at T N , which is independent of external magnetic field up to 9 T with an entropy content as expected for Mn 3+ ions. The temperature-dependent dielectric constant displays a distinct anomaly at T N .