Related papers: Topotactically induced oxygen vacancy order in nic…
Recently, the signatures of superconductivity near 80 K have been discovered in the single crystal of La3Ni2O7 under pressure, which makes it a new candidate of the high-temperature superconductors dominated by 3d transition elements after…
In this study, we synthesized single crystals of Na$_{x}$CoO$_{2}$ with $x\sim0.8$ using the optical floating zone technique. A thorough electrochemical treatment of the samples permitted us to control the de-intercalation of Na to obtain…
We present a systematic density functional theory (DFT) plus Hubbard $U$ study of structural trends and the stability of different magnetically ordered states across the rare-earth nickelate series, $R$NiO$_3$, with $R$ from Lu to La. In…
We report a systematic study on the crystal growth of the rare-earth titanates $R_2$Ti$_2$O$_7$ ($R$ = Gd, Tb, Dy, Ho, Y, Er, Yb and Lu) and Y-doped Tb$_{2-x}$Y$_x$Ti$_2$O$_7$ ($x$ = 0.2 and 1) using an optical floating-zone method.…
Phase selection in Ti-Zr-Hf-Al high-entropy alloys was investigated by in-situ high-energy X$-$ray diffraction, single-crystal X$-$ray diffraction, and density-functional theory based electronic-structure methods that address disorder and…
Iron oxides play an increasingly prominent role in heterogeneous catalysis, hydrogen production, spintronics and drug delivery. The surface or material interface can be performance limiting in these applications, so it is vital to determine…
The synthesis of high-quality Ruddlesden-Popper (RP) nickelates remains challenging due to variations in oxygen content and the prevalence of intergrown RP phases. Precisely controlling the stoichiometry and characterizing the resulting…
A defining signature of strongly correlated electronic systems is the existence of competing phases with similar ground state energies, resulting in a rich phase diagram. While in the recently discovered nickelate superconductors, a high…
The emergence of magnetism in otherwise nonmagnetic compounds and its underlying mechanisms have become the subject of intense research. Here we demonstrate that the nonmagnetic oxygen vacancies are responsible for an unconventional…
I report on the experimental confirmation that critical percolation statistics underlie the ordering kinetics of twisted nematic phases in the Allen-Cahn universality class. Soon after the ordering starts from a homogeneous disordered phase…
Defect engineering has brought about a unique level of control for Si-based semiconductors, leading to the optimization of various opto-electronic properties and devices. With regard to perovskite transition metal oxides, oxygen vacancies…
Anisotropies in electronic transportations conventionally originate from the nature of low symmetries in crystal structures, and were not anticipated for perovskite oxides, the crystal asymmetricity of which is far below, e.g. van der Waals…
The defect stability in a prototypical perovskite oxide superlattice consisting of SrTiO$_3$ and PbTiO$_3$ (STO/PTO) is determined using first principles density functional theory calculations. Specifically, the oxygen vacancy formation…
We report an experimental and theoretical analysis of the sqrt(3)x sqrt(3)-R30 and 2x2 reconstructions on the NiO (111) surface combining transmission electron microscopy, x-ray photoelectron spectroscopy, and reasonably accurate density…
Controlling lattice oxygen reactivity in earth abundant OER catalysts requires precise tuning of defect chemistry in the oxide lattice. Here, we combine DFT+U calculations with plasma assisted synthesis to show how O2 and H2O in the…
Understanding the electronic behavior of Ni$^{2+}$ in a square planar environment of oxygen is the key to unravel the origin of the recently discovered superconductivity in the hole doped nickelate Nd$_{0.8}$Sr$_{0.2}$NiO$_2$. To identify…
The crystal structure and oxygen stoichiometry in two-layer Na0.74CoO2 and Na0.38CoO2 at room temperature are analyzed by powder neutron diffraction. Two sets of diffraction data for each sample, taken at different incident neutron…
The spin, charge, and lattice degrees of freedom and their interplay in high entropy oxides were intensively investigated in recent years. However, how the orbital degree of freedom is affected by the extreme disorder in high entropy oxides…
Topochemical fluorination offers a low--temperature route for modifying the anion chemistry and electronic ground states of layered transition-metal oxides, providing access to metastable phases and functionalities that are not able to be…
Oxygen vacancies in the perovskite insulator SrTiO$_3$ free electrons that couple with other physical degrees of freedom such as lattice, orbital, and spin. This leads to the emergence of exotic quantum states such as superconductivity and…