Giant Electrothermal Conductivity and Spin-Phonon Coupling in an Antiferromagnetic Oxide

Abstract

The application of weak electric fields ( less, similar 100 V/cm) is found to dramatically enhance the lattice thermal conductivity of the antiferromagnetic insulator CaMnO3 over a broad range of temperature about the Néel ordering point (125 K). The effect is coincident with field-induced detrapping of bound electrons, suggesting that phonon scattering associated with short- and long-ranged antiferromagnetic order is suppressed in the presence of the mobilized charge. This interplay between bound charge and spin-phonon coupling might allow for the reversible control of spin fluctuations using weak external fields.

Study of spin-ordering and spin-reorientation transitions in hexagonal manganites through Raman spectroscopy

“…The broad bands of 520–630 cm −1 and 710–880 cm −1 would be mainly originated from magnon scattering2122232425. The Raman spectroscopy of hexagonal manganites has been extensively studied, these studies were focused on phonon vibrations and spin-phonon coupling6781920262728. The Raman studies of magnon scattering in hexagonal manganites were attempted more than a decade ago2930.…”

“…Raman spectroscopy of phonon scattering has been widely applied to investigate crystallographic phase transitions12345; it offers an opportunity as a sensitive probe for the study of crystal structure changes. In magnetic materials, Raman spectroscopy of phonon scattering can also be applied to investigate magnetic phase transitions if spin-phonon coupling has clear influence on phonon scattering67891011. Generally spin-phonon coupling has weak influence on phonon scattering; thus Raman study of phonons could only be helpful to investigate spin-ordering transitions.…”

Lattice dynamics and thermal transport in multiferroicCuCrO2

“…Furthermore, ultrasonic measurements in delafossite compounds have indicated substantial softening of elastic constants near T N [16,27]. A possible signature of spin-phonon coupling can also be found in reported thermal conductivity measurements of YMnO 3 or CaMnO 3 [28][29][30], motivating studies of the role of the spin-phonon interaction on phonon scattering rates. The strong dynamic coupling between spin fluctuations and phonons in YMnO 3 and CaMnO 3 lead to suppression of thermal transport in paramagnetic state.…”

The effect of magnetic order on the thermal transport properties of the intrinsic two-dimensional magnet 2H-VSe2

“…[20][21][22][23][24] Therefore, a systematic study of the thermal transport properties of materials including magnetic materials could provide an extremely valuable guideline for their practical applications. On the other hand, unlike the phonons (electrons) dominating the thermal transport in semiconductors and insulators (metals), the long-range magnetic order in magnetic materials will be coupled with the lattice vibrations, [25][26][27] which will affect the thermal transport properties. Previous research studies have also paid attention to this point; nevertheless, their conclusions are still controversy.…”