Magnetic ground state of the Ising-like antiferromagnet DyScO3

Abstract

We report the low temperature magnetic properties of the DyScO3 perovskite, which were characterized by means of single crystal and powder neutron scattering, and by magnetization measurements. Below TN = 3.15 K, Dy 3+ moments form an antiferromagnetic structure with an easy axis of magnetization lying in the ab-plane. The magnetic moments are inclined at an angle of ∼ ±28 • to the b-axis. We show that the ground state Kramers doublet of Dy 3+ is made up of primarily |±15/2 eigenvectors and well separated by crystal field from the first excited state at E1 = 24.9 meV. This leads to an extreme Ising single-ion anisotropy, M ⊥ /M ∼ 0.05. The transverse magnetic fluctuations, which are proportional to M 2 ⊥ /M 2 , are suppressed and only moment fluctuations along the local Ising direction are allowed. We also found that the Dy-Dy dipolar interactions along the crystallographic c-axis are 2-4 times larger than in-plane interactions.

Antiferromagnetic ordering and dipolar interactions of YbAlO3

“…It turns out that YbAlO 3 , as well as a few other materials for which the angles α and ϕ were reported [13,[23][24][25], are located in the vicinity of this 'magic' line, as indicated by the stars in Fig. 4(b).…”

“…The calculation of the ground state wave functions and the CEF configuration was based on the point charge model [20, [26][27][28]. As in the case of the iso-structural compound DyScO 3 [13], the first twelve nearest oxygen neighbors around the Yb 3+ ion are considered ( Fig. 1(b)), which keeps the correct local point group symmetry (C s ) of the Yb site.…”

“…This intra-plane dipolar interaction depends on the relative tilting angle ϕ of the Ising moments [30], and depending on the value of ϕ, the ground state may be the configuration G xAy or Ax G y. For the case of YbAlO 3 with ϕ = 23.5 • , the configuration Ax G y is selected, while in the iso-structural compound DyScO 3 with ϕ = 90 • + 28 • = 118 • , configuration G xAy is selected [13].…”

“…The instrumental resolution (gray bar) is estimated from the full width at half maximum (FWHM) of the magnetic (001) peak measured at 50 mK. The following function [13,31] was adopted to describe the magnetic structure factor:…”

“…The ground state doublets have a strong uniaxial anisotropy, which constrains the magnetic moments in the ab-plane with angle α to the a-axis, and depending on α dipolar interchain interaction determine the type of AFM ordering. However, distinct from DyScO 3 , in which case neither the transverse nor the longitudinal fluctuations are seen in inelastic neutron scattering, due to the strong Ising single-ion anisotropy and the constraint of the ∆S = 1 selection rule [13], the analysis of the YbAlO 3 ground states wavefunctions shows that the longitudinal fluctuations are visible to neutrons, making it a perfect object for exploring one-dimensional quantum magnetism.…”