Publications
Showing 85 results for Author: Yaohua Liu
Mar, 2026
Journal
Persistent structural distortion for anticipated improper ferroelectricity in ultrathin h-Lu1−xCaxMnO3 films
Improper ferroelectricity in hexagonal rare-earth manganites (h-RMnO3, R = Ho–Lu, Y, Sc) arises from a geometric distortion as the primary order parameter, resilient to depolarizing fields and promising for ultrathin ferroelectric devices. However, the substrate-induced interface clamping effect, which suppresses the geometric distortion in the sub-nanometer regime, has th…
Jan, 2026
Journal
Pervasive symmetry-lowering nanoscale structural fluctuations in the cuprate La2−𝑥Sr𝑥CuO4
The cuprate superconductors are among the most widely studied quantum materials, yet there remain fundamental open questions regarding their electronic properties and the role of structural degrees of freedom. Recent neutron and x-ray scattering measurements uncovered exponential scaling with temperature of the strength of orthorhombic fluctuations in the tetragonal phase…
Dec, 2025
Journal
Criticality and Magnetic Phases of Ising Shastry–Sutherland Candidate Holmium Tetraboride
Frustrated magnetic systems arising in geometrically constrained lattices represent rich platforms for exploring unconventional phases of matter, including fractional magnetization plateaus, incommensurate orders and complex domain dynamics. However, determining the microscopic spin configurations that stabilize such phases is a key challenge, especially when in-plane and…
Mar, 2025
Journal
Optical design for the single crystal neutron diffractometer Pioneer
Pioneer is a single-crystal neutron diffractometer optimized for small-volume samples and weak signals at the Second Target Station at Oak Ridge National Laboratory. This paper presents the preliminary optical design progress, focusing on the rationale behind key design choices. It covers the T0 and bandwidth disk choppers, guide and beam control system, incident-beam pola…
Mar, 2025
Journal
Incident beam optics optimization for the single crystal neutron diffractometer Pioneer with a polarized beam option
Pioneer, a next-generation single-crystal neutron diffractometer, is under development for Oak Ridge National Laboratory’s Second Target Station. Designed to address a wide range of scientific questions, Pioneer will deliver homogeneous neutron beams with customizable size and divergence and provide a polarized beam option. This article introduces its incident beam optics,…
Feb, 2025
Journal
Microstructural Underpinnings of Giant Intrinsic Exchange Bias in Epitaxial NiCo2O4 Thin Films
Understanding intrinsic exchange bias in nominally single-component ferromagnetic or ferrimagnetic materials is crucial for simplifying related device architectures. However, the mechanisms behind this phenomenon and its tunability remain elusive, which hinders the efforts to achieve unidirectional magnetization for widespread applications. Inspired by the high tunability…
Jan, 2025
Journal
Structural properties of plastically deformed SrTiO3 and KTaO3
Dislocation engineering has the potential to open new avenues toward the exploration and modification of the properties of quantum materials. Strontium titanate (SrTiO3, STO) and potassium tantalate (KTaO3, KTO) are incipient ferroelectrics that show metallization and superconductivity at extremely low charge-carrier concentrations and have been the subject of resurgent…
Dec, 2024
Journal
Integrated edge-to-exascale workflow for real-time steering in neutron scattering experiments
We introduce a computational framework that integrates artificial intelligence (AI), machine learning, and high-performance computing to enable real-time steering of neutron scattering experiments using an edge-to-exascale workflow. Focusing on time-of-flight neutron event data at the Spallation Neutron Source, our approach combines temporal processing of four-dimensional…
Oct, 2024
Journal
Intrinsic exchange bias from interfacial reconstruction in an epitaxial NixCoyFe3−x−yO4(111)/α-Al2O3(0001) thin film family
Intrinsic exchange bias is known as the unidirectional exchange anisotropy that emerges in a nominally single-component ferro-(ferri-)magnetic system. In this work, with magnetic and structural characterizations, we demonstrate that intrinsic exchange bias is a general phenomenon in (Ni, Co, Fe)-based spinel oxide films deposited on α-Al2O3(0001) substrates, due to the eme…