Engineering topics

Chang, Lieh-Jeng

Publications and source records attributed to Chang, Lieh-Jeng.

3 records

DOE OSTI2023

Spiral spin cluster in the hyperkagome antiferromagnet Mn 3 RhSi

Local spin correlation orders emerge in a paramagnetic state, with notable examples such as the partial order, cooperative paramagnetism, and soliton spin liquid. The noncentrosymmetric intermetallic antiferromagnet Mn 3 RhSi also exhibits the local spin correlation order in the paramagnetic state as magnetic short-range order in a wide temperature range. Here, we show that the local spin correlation order has a spiral structure by neutron scattering measurement of a Mn 3 RhSi single crystal. The possible origins of the magnetic cluster formation are discussed in terms of the Lifshitz invariant and the Griffiths phase, and compared with the room-temperature skyrmion phase of Co 7 Zn 7 Mn 6 and non-Fermi liquid behavior of β-Mn.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2021

Spin-flop Phase in a Honeycomb Antiferromagnet Mn 0.84 Mg 0.16 TiO 3

The spin-flop phase of a honeycomb antiferromagnet of Mn 0.84 Mg 0.16 TiO 3 has been studied under magnetic field along normal direction to the honeycomb plane by neutron scattering. With increasing a magnetic field from 0 to 5 T, the inelastic scattering intensity increased by 1.5 times at (1 0 0), where the magnetic structure was found to be collinear-antiferromagnet with the spin parallel to [1 1 0] direction. The spin direction is consistent with a 1.5 times increase of the inelastic intensity. Furthermore, the negligible energy difference between K and K' points suggests small values for both Dzyaloshinskii–Moriya interaction and bond-dependent symmetric anisotropic exchange interaction in this material.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2020

High-temperature short-range order in Mn 3 RhSi

Conventional phase transitions are well understood in terms of the order parameter, based on the Landau–Ginzburg–Wilson theory. However, unconventional magnetic orders have been observed in clean systems such as MnSi. The unconventional magnetic orders of conduction electrons in the metallic phase has been observed for high-temperature superconductors and heavy fermion compounds. However, these unconventional magnetic orders have been limited to relatively low temperatures as quantum phase transitions. Here high-temperature magnetic short-range order is observed as one of the unconventional magnetic orders at temperatures up to 720 K in a noncentrosymmetric intermetallic antiferromagnet Mn 3 RhSi with a well-ordered lattice. The magnetic Mn ions form a hyperkagome network of corner-sharing triangles, where the spins are geometrically frustrated. The spin network is equivalent to that of a spin liquid and non-Fermi-liquid material, β-Mn. Our observation indicates that a metallic phase with magnetic short-range order exists at high temperatures.

36 MATERIALS SCIENCE↗