Magnetic properties of monoclinic lanthanide orthoborates, $Ln$BO${}_3$, $Ln$ = Gd, Tb, Dy, Ho, Er, Yb

Abstract

The lanthanide orthoborates, $Ln$BO${}_3$, $Ln$ = Gd, Tb, Dy, Ho, Er, Yb crystallise in a monoclinic structure with the magnetic $L{n}^{3+}$ forming an edge-sharing triangular lattice. The triangles are scalene, however all deviations from the ideal equilateral geometry are less than 1.5%. The bulk magnetic properties are studied using magnetic susceptibility, specific heat and isothermal magnetisation measurements. Heat capacity measurements show ordering features at $T\le$ 2 K for $Ln$ = Gd, Tb, Dy, Er. No ordering is observed for YbBO${}_3$ at $T\ge$ 0.4 K and HoBO${}_3$ is proposed to have a non-magnetic singlet state. Isothermal magnetisation measurements indicate isotropic Gd${}^{3+}$ spins and strong single-ion anisotropy for the other $L{n}^{3+}$. The change in magnetic entropy has been evaluated to determine the magnetocaloric effect in these materials. GdBO${}_3$ and DyBO${}_3$ are found to be competitive magnetocaloric materials in the liquid helium temperature regime.

19 pages, 8 figures, 2 supplementary figures, accepted for publication in Materials Research Bulletin

References in corpus (9)

• Slow Magnetic Order-Order Transition in the Spin Chain Antiferromagnet Ca3Co2O6
• Enhanced magnetocaloric effect from Cr substitution in Ising lanthanide gallium garnets $L{n}_3{\text{CrGa}}_4{\text{O}}_{12}$ ($Ln$ = Tb, Dy, Ho)
• Low-temperature magnetic ordering in SrEr${}_2$O${}_4$
• Disorder from order among anisotropic next-nearest-neighbor Ising spin chains in SrHo${}_2$O${}_4$
• Low-temperature magnetism in the honeycomb systems SrLn2O4
• 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
• Dispersionless spin waves in Gadolinium Gallium Garnet
• Magnetic properties of geometrically frustrated SrGd2O4
• Helical magnetism and structural anomalies in triangular lattice α-SrCr2O4