Effect of A-site Fe substitution on the magnetic behavior of Dy 2 Ti 2 O 7 spin ice

Abstract

Geometrically frustrated Dy 2 Ti 2 O 7 spin ice is known for robust magnetic behavior where structural and dielectric properties are coupled with its magnetism. Herein, effects of Fe substitution, at the magnetic Dy site (0 ≤ x ≤ 0.15) in Dy 2 Ti 2 O 7 compound have been systematically examined in terms of structural distortions and magnetic perturbations through structural, dielectric, optical and magnetic studies. The experimental findings suggest that Fe substitution does not change the crystal electric field acting on the rare earth ion, though it produces significant structural distortions. These findings suggest that spin dynamics non-monotonically depends on the nature and dynamics of neighboring magnetic ion's spin (Fe spin in this case), because of existing strong spin correlations. This dependency provides a new possibility to tune or modify the spin dynamics of the correlated magnetic states in these materials via magnetic perturbations, which can be controlled by the externally applied magnetic field. © 2019 Elsevier B.V.