Structural evolution and skyrmionic phase diagram of the lacunar spinel GaMo${}_4$Se${}_8$

Abstract

In the $A{B}_4{Q}_8$ lacunar spinels, the electronic structure is described on the basis of inter- and intra-cluster interactions of tetrahedral $B_4$ clusters, and tuning these can lead to myriad fascinating electronic and magnetic ground states. In this work, we employ magnetic measurements, synchrotron X-ray and neutron scattering, and first-principles electronic structure calculations to examine the coupling between structural and magnetic phase evolution in GaMo${}_4$Se${}_8$, including the emergence of a skyrmionic regime in the magnetic phase diagram. We show that the competition between two distinct Jahn-Teller distortions of the room temperature cubic $F\overline{4}3m$ structure leads to the coexistence of the ground state $R3m$ phase and a metastable $Imm2$ phase. The magnetic properties of these two phases are computationally shown to be very different, with the $Imm2$ phase exhibiting uniaxial ferromagnetism and the $R3m$ phase hosting a complex magnetic phase diagram including equilibrium Néel--type skyrmions stable from nearly $T$ = 28 K down to $T$ = 2 K, the lowest measured temperature. The large change in magnetic behavior induced by a small structural distortion reveals that GaMo${}_4$Se${}_8$ is an exciting candidate material for tuning unconventional magnetic properties $via$ mechanical means.

References in corpus (5)

• Spin-wave spectroscopy on Dzyaloshinskii-Moriya interaction in room-temperature chiral magnets hosting skyrmions
• Deciphering structural and magnetic disorder in the chiral skyrmion host materials Co${}_x$Zn${}_y$Mn${}_z$ ($x+y+z=20$)
• Direct experimental observation of the molecular Jeff=3/2 ground state in the lacunar spinel GaTa4Se8
• Mapping Skyrmion Stability in Uniaxial Lacunar Spinel Magnets from First-Principles
• Controlling Dzyaloshinskii-Moriya interactions in the skyrmion host candidates FePd${}_{1-x}$Pt${}_x$Mo${}_3$N

Cited by in corpus (6)

• Potential Skyrmion Host Fe(IO3)3: Connecting Stereo-active Lone-Pair Electron Effects to the Dzyaloshinskii-Moriya Interaction
• Magnetoentropic mapping and computational modeling of cycloids and skyrmions in the lacunar spinels GaV${}_4$S${}_8$ and GaV${}_4$Se${}_8$
• Cluster rearrangement by chiral charge order in lacunar spinel GaNb${}_4$Se${}_8$
• Entropic signatures of the skyrmion lattice phase in MnSi1-xAlx and Fe1-yCoySi
• Anomalous magnetoentropic response of skrymion crystals
• Structure and magnetism of the skyrmion hosting family GaV${}_4$S${}_{8-y}$Se${}_y$ with low levels of substitutions between $0\le y\le 0.5$ and $7.5\le y\le 8$