Single crystal synthesis and characterization of proposed eight-fold degenerate topological material Bi2PdO4

Abstract

Materials with nonsymmorphic symmetries have numerous applications and have recently come to the forefront as potentially containing novel topological states of matter, such as eight-fold fermions. In this paper, we report the single crystal growth of eight-fold degenerate topological material, Bi2PdO4 via melt-growth technique. The structural properties and chemical composition are confirmed by X-ray diffraction (XRD) and energy-dispersive x-ray analysis studies, respectively. Powder XRD shows that Bi2PdO4 crystallizes in the tetragonal P4/ncc (#130) type structure which is made up of PdO4 square planar units along the c direction. Because of the decreasing trend of magnetization with field, this sample exhibits room temperature diamagnetism. Our temperature dependent resistivity measurement suggests the semiconducting nature of the compound with an estimated band gap of ∼153 meV from Arrhenius fitting. Our Raman spectroscopy data shows peak shifting with decreasing temperature from 300 K to 100 K. Our density functional theory calculation suggests eightfold band crossing at the A point. From our DFT calculations, we determined a band gap of 176 meV in the absence of Spin-Orbit Coupling (SOC) and 180 meV with SOC. This aligns with our experimental observations. Finally, our present study provides a new direction for further transport and spectroscopic investigation in this compound.