Dispersionless spin waves in Gadolinium Gallium Garnet

Abstract

We report the results of neutron scattering on a powder sample of Gd3Ga5O12 at high magnetic fields. We find that in high fields (B>1.8 T) the system is not fully polarized, but has a small canting of the moments induced by the dipolar interaction. We show that the degree of canting is accurately predicted by the standard Hamiltonian which includes the dipolar interaction. The inelastic scattering is dominated at large momentum transfers by a band of almost dispersionless excitations. We show that these correspond to the spin waves localized on ten site rings, expected for a system described by a nearest neighbor interaction, and that the spectrum at high fields B>1.8 T is well-described by a spin wave theory. The phase for fields <1.8 T is characterized by an antiferromagnetic Bragg peak at (210) and an incommensurate peak.

5 pages, 4 figures

References in corpus (3)

• Updating the phase diagram of the archetypal frustrated magnet Gd3Ga5O12
• Macroscopic signature of protected spins in a dense frustrated magnet
• Field induced magnetic order in the frustrated magnet Gadolinium Gallium Garnet

Cited by in corpus (8)

• Magnetic properties of monoclinic lanthanide orthoborates, $Ln$BO${}_3$, $Ln$ = Gd, Tb, Dy, Ho, Er, Yb
• Sensitivity of magnetic properties to chemical pressure in lanthanide garnets $L{n}_3{A}_2{X}_3{\text{O}}_{12}$, $Ln$ = Gd, Tb, Dy, Ho, $A$ = Ga, Sc, In, Te, $X$ = Ga, Al, Li
• Magnetic properties of monoclinic lanthanide metaborates, $Ln$(BO${}_2$)${}_3$, $Ln$ = Pr, Nd, Gd, Tb
• Terahertz response of gadolinium gallium garnet (GGG) and gadolinium scandium gallium garnet (SGGG)
• Persistence of the flat band in a kagome magnet with dipolar interactions
• Anisotropic phase diagram and spin fluctuations of the hyperkagome magnet Gd3Ga5O12 as revealed by sound velocity measurements
• Absence of magnetic ordering and field induced phase diagram in the Gadolinium Aluminium garnet
• Relieving the frustration through Mn${}^{3+}$ substitution in Holmium Gallium Garnet