Epitaxial thin films of Dirac semimetal antiperovskite Cu3PdN
C. X. Quintela,
N. Campbell,
D. F. Shao,
J. Irwin,
D. T. Harris,
L. Xie,
T. J. Anderson,
N. Reiser,
X. Q. Pan,
E. Y. Tsymbal,
M. S. Rzchowski,
C. B. Eom
Affiliations
C. X. Quintela
Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
N. Campbell
Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
D. F. Shao
Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska 68588, USA
J. Irwin
Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
D. T. Harris
Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
L. Xie
National Laboratory of Solid State Microstructures and College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu 210093, People’s Republic of China
T. J. Anderson
Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
N. Reiser
Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
X. Q. Pan
Department of Chemical Engineering and Materials Science, University of California Irvine, Irvine, California 92697, USA
E. Y. Tsymbal
Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska 68588, USA
M. S. Rzchowski
Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
C. B. Eom
Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
The growth and study of materials showing novel topological states of matter is one of the frontiers in condensed matter physics. Among this class of materials, the nitride antiperovskite Cu3PdN has been proposed as a new three-dimensional Dirac semimetal. However, the experimental realization of Cu3PdN and the consequent study of its electronic properties have been hindered due to the difficulty of synthesizing this material. In this study, we report fabrication and both structural and transport characterization of epitaxial Cu3PdN thin films grown on (001)-oriented SrTiO3 substrates by reactive magnetron sputtering and post-annealed in NH3 atmosphere. The structural properties of the films, investigated by x-ray diffraction and scanning transmission electron microscopy, establish single phase Cu3PdN exhibiting cube-on-cube epitaxy (001)[100]Cu3PdN||(001)[100]SrTiO3. Electrical transport measurements of as-grown samples show metallic conduction with a small temperature coefficient of the resistivity of 1.5 × 10−4 K−1 and a positive Hall coefficient. Post-annealing in NH3 results in the reduction of the electrical resistivity accompanied by the Hall coefficient sign reversal. Using a combination of chemical composition analyses and ab initio band structure calculations, we discuss the interplay between nitrogen stoichiometry and magneto-transport results in the framework of the electronic band structure of Cu3PdN. Our successful growth of thin films of antiperovskite Cu3PdN opens the path to further investigate its physical properties and their dependence on dimensionality, strain engineering, and doping.
