Epitaxial thin films of hexagonal BaRuO3 on (001) SrTiO3

We report the growth, epitaxial arrangement, and electrical and magnetic properties of epitaxial thin films of hexagonal BaRuO3 on (001) cubic perovskite substrates. Four-circle x-ray diffraction reveals that the BaRuO3 films are predominantly grown with two distinct orientations normal to the (001) SrTiO3 substrate: (022̄3) of the four-layered hexagonal structure (4H) in the sputter-grown films and (202̄5) of the nine-layered hexagonal structure (9R) in the pulsed laser deposited films. (022̄3)-oriented 4H films consist of four orthogonal domains with the in-plane relationship of BaRuO3[21̄1̄0]//SrTiO3〈110〉. The temperature dependent resistivity of the (022̄3) 4H film shows metallic behavior. In contrast, a resistivity minimum is observed at low temperatures in the (202̄5) 9R film. Both films exhibit Pauli paramagnetism.