Quantum criticality in geometrically frustrated Ho 2 Ti 2 O 7 and Dy 2 Ti 2 O 7 spin ices

Abstract

Geometrically frustrated magnetic materials possess multiple exotic states associated by lattice architecture induced competing magnetic interactions. It has been found that in case of Ho 2 Ti 2 O 7 , where quantum critical region existed up to ∼28.5 K, both single ion spin freezing (T f ) and spin ice freezing (T ice ) follows the (H − H C ) 1/2 variation with different values of the critical field. Where as in case of Dy 2 Ti 2 O 7 , it follows a liner relation. Accordingly, a H-T phase diagram, for this spin freezing phenomenon, has been presented for these compounds. The studies on magnetically distorted Ho 2 Ti 1 . 9 Mn 0 . 1 O 7 & Dy 2 Ti 1 . 9 Mn 0 . 1 O 7 compounds, lead us to conclude that competing magnetic interactions acting in different temperature regime are one of the preliminary factors responsible for the alteration in quantum critical point. These results provide a new platform for the experimental investigation and description of multiple exotic states occurring in frustrated magnets in term of quantum criticality. © 2019 Elsevier B.V.