Publications

Nov, 2023

Journal

Static and dynamical properties of the spin-52 nearly ideal triangular lattice antiferromagnet Ba3MnSb2O9

We study the ground state and spin excitations in Ba3MnSb2O9, an easy-plane S=5/2 triangular lattice antiferromagnet. By combining single-crystal neutron scattering, electric spin resonance (ESR), and spin wave calculations, we determine the frustrated quasi-two-dimensional spin Hamiltonian parameters describing the material. While the material has a slight monoclinic stru…

Nov, 2023

Journal

Studies on the structure and the magnetic properties of high-entropy spinel oxide (MgMnFeCoNi)Al2O4

The study of high-entropy materials has attracted enormous interest since they could show new functional properties that are not observed in their related parent phases. Here, we report single crystal growth, structure, thermal transport, and magnetic property studies on a novel high-entropy oxide with the spinel structure (MgMnFeCoNi)Al2O4. We have successfully grown high…

Nov, 2023

Journal

Magnetic Frustration Driven by Itinerancy in Spinel CoV2O4

Localized spins and itinerant electrons rarely coexist in geometrically-frustrated spinel lattices. They exhibit a complex interplay between localized spins and itinerant electrons. In this paper, we study the origin of the unusual spin structure of the spinel CoV2O4, which stands at the crossover from insulating to itinerant behavior using the first principle calculation…

Nov, 2023

Journal

“Forbidden” phonon: dynamical signature of bond symmetry breaking in the iron chalcogenides

Nov, 2023

Journal

Successive field-induced transitions in BiFeO3 around room temperature

Nov, 2023

Journal

Soft antiphase tilt of oxygen octahedra in the hybrid improper multiferroic Ca3Mn1.9Ti0.1O7

We report a single crystal neutron and x-ray diffraction study of the hybrid improper multiferroic Ca3Mn1.9Ti0.1O7 (CMTO), a prototypical system where the electric polarization arises from the condensation of two lattice distortion modes. With increasing temperature (T), the out-of-plane, antiphase tilt of MnO6 decreases in amplitude while the in-plane, in-phase rotation r…

Nov, 2023

Journal

New capabilities in high-resolution neutron Larmor diffraction at ORNL

Using superconducting magnetic Wollaston prisms, high-resolution neutron Larmor diffraction has been implemented at the High-Flux Isotope Reactor of Oak Ridge National Laboratory (ORNL), Tennesse, USA. This technique allows the inverse relationship between the achievable diffraction resolution and the usable neutron flux to be overcome. Instead of employing physically tilt…

Nov, 2023

Conference Paper

Polarized neutron diffraction study in helical magnetic phases of MnP

MnP shows an interesting magnetic phase diagram under pressure up to ∼7.5 GPa, where magnetic long range order disappears and superconductivity appears. Polarized neutron analyses were applied to two different helical magnetic structures (helical-c and helical-b). Helicity was observed in the both structures. The two helical domain ratio becomes more unbalanced in the heli…

Nov, 2023

Journal

Magnetic structure and dispersion relation of S=1/2 quasi-one-dimensional Ising-like antiferromagnet BaCo2V2O8 in transverse magnetic field

Nov, 2023

Journal

Static and dynamic spin properties in the quantum triangular lattice antiferromagnet Ag2CoO2

In Ag2CoO2, Co forms triangular lattice layers, which are separated by the metallic (Ag2) block. The magnetic susceptibility and heat capacity measurements show that this material exhibits an antiferromagnetic transition at TN=17.5 K and the Weiss temperature (TΘ) and the effective moment are −274 K and 1.62μB, respectively, indicating that the Co ion carries spin (S) 1/2…

Nov, 2023

Journal

Highly dispersive magnons with spin-gap-like features in the frustrated ferromagnetic S=12 chain compound Ca2Y2Cu5O10 detected by inelastic neutron scattering

We report inelastic neutron scattering experiments in Ca2Y2Cu5O10 and map out the full one-magnon dispersion which extends up to a record value of 53 meV for frustrated ferromagnetic (FM) edge-sharing CuO2 chain (FFESC) cuprates. A homogeneous spin-1/2 chain model with a FM nearest-neighbor (NN), an antiferromagnetic (AFM) next-nearest-neighbor (NNN) inchain, and two diago…

Nov, 2023

Journal

Wide-angle diamond cell for neutron scattering

A new diamond cell with extreme apertures is described. It is tailored for a large variety of neutron scattering techniques such as inelastic neutron scattering and single-crystal diffraction both at the Spallation Neutron Source (SNS) and the High Flux Isotope Reactor at the Oak Ridge National Laboratory. Simple springs enable forces of over 10 metric tons to be clamped i…