Publications

Sep, 2024

Journal

Oxygen vacancy formation energies in PbTiO3/SrTiO3 superlattice

The defect stability in a prototypical perovskite oxide superlattice consisting of SrTiO3 and PbTiO3 (STO/PTO) is determined by using first principles density functional theory calculations. Specifically, the oxygen vacancy formation energies Ev in the paraelectric and ferroelectric phases of a superlattice with four atomic layers of STO and four layers of PTO (4STO/4PTO)…

Sep, 2024

Journal

Putting error bars on density functional theory

Predicting the error in density functional theory (DFT) calculations due to the choice of exchange–correlation (XC) functional is crucial to the success of DFT, but currently, there are limited options to estimate this a priori. This is particularly important for high-throughput screening of new materials. In this work, the structure and elastic properties of binary and te…

Dec, 2023

Journal

Insulating antiferromagnetism in VTe

We report a detailed theoretical and experimental study on the vanadium monotelluride VTe, which crystallizes in the NiAs hexagonal structure. First-principles calculations reveal a complex hierarchy of magnetic interactions and energy scales, with the ground state theoretically determined as an (12, 0, 12) antiferromagnetic ordering with insulating character and a band ga…

Dec, 2023

Journal

Emerging edge states on the surface of the epitaxial semimetal CuMnAs thin film

Epitaxial thin films of CuMnAs have recently attracted attention due to their potential to host relativistic antiferromagnetic spintronics and exotic topological physics. Here, we report on the structural and electronic properties of a tetragonal CuMnAs thin film studied using scanning tunneling microscopy (STM) and density functional theory (DFT). STM reveals a surface te…

Dec, 2023

Journal

Tuning magnetic order in the van der Waals metal Fe5GeTe2 by cobalt substitution

Fe5−xGeTe2 is a van der Waals material with one of the highest reported bulk Curie temperatures, TC≈310K. In this study, theoretical calculations and experiments are utilized to demonstrate that the magnetic ground state is highly sensitive to local atomic arrangements and the interlayer stacking. Cobalt substitution is found to be an effective way to manipulate the magnet…

Dec, 2023

Journal

Probing the local site disorder and distortion in pyrochlore high-entropy oxides

High-entropy oxides (HEOs) have attracted great interest in diverse fields because of their inherent opportunities to tailor and combine materials functionalities. The control of local order/disorder in the class is by extension a grand challenge toward realizing their vast potential. Here we report the first examples of pyrochlore HEOs with five M-site cations, for Nd2M2O…

Dec, 2023

Journal

Unintended consequence of topochemical reduction of SrFeO3 to SrFeO2: Design of infinite layered oxides

The infinite layer structure type has been known to host high-temperature superconductivity since the discovery of Ca0.86Sr0.14CuO2, yet little progress has been made to synthesize many analogs. Here, using SrFeOx as a prototype system, we explore the thermodynamic obstacles behind the scarcity of 3d elements adopting the infinite layer structure type. In this context, syn…

Dec, 2023

Journal

Role of Pairwise Reactions on the Synthesis of Li 0.3 La 0.57 TiO 3 and the Resulting Structure–Property Correlations

The performance of single-ion conductors is highly sensitive to the material’s defect chemistry. Tuning these defects is limited for solid-state reactions as they occur at particle–particle interfaces, which provide a complex evolving energy landscape for atomic rearrangement and product formation. In this report, we investigate the (1) order of addition and (2) lithium pr…

Nov, 2023

Journal

Constructing a magnetic handle for antiferromagnetic manganites

Thin superlattices with 1:2 ratio of bulk antiferromagnetics SrMnO3 :RMnO3 (R=Lantanide) are known to exhibit ferrmagnetism due to electronic reconstruction. In this study the limited range of the charge transfer is used to generate thin ferromagnetic layers adjacent to A-type antiferromag- netic order in superlattices with thicker RMnO3 layers. The ferromagnetic layers st…

Nov, 2023

Journal

Continuum Model of Gas Uptake for Inhomogeneous Fluids

We describe a continuum model of gas uptake for inhomogeneous fluids (CMGIF) and use it to predict fluid adsorption in porous materials directly from gas-substrate interaction energies determined by first principles calculations or accurate effective force fields. The method uses a perturbation approach to correct bulk fluid interactions for local inhomogeneities caused by…

Nov, 2023

Journal

High-temperature magnetostructural transition in van der Waals-layered α-MoCl3

The crystallographic and magnetic properties of the cleavable 4d3 transition metal compound α−MoCl3 are reported, with a focus on the behavior above room temperature. Crystals were grown by chemical vapor transport and characterized using temperature dependent x-ray diffraction, Raman spectroscopy, and magnetization measurements. A structural phase transition occurs near 5…

Nov, 2023

Journal

Magnetic behavior and spin-lattice coupling in cleavable van der Waals layered CrCl3 crystals