Influence of the Magnetic Sub-Lattices in the Double Perovskite Compound LaCaNiReO$_6$

TL;DR

This study investigates the complex magnetic behavior of LaCaNiReO$_6$ double perovskite using $5$SR and magnetic susceptibility, revealing a dynamic phase transition and magnetic domain formation across multiple temperature regimes.

Contribution

The paper provides new insights into the temperature-dependent magnetic phases and sublattice interactions in LaCaNiReO$_6$, highlighting a previously unreported dynamic phase transition.

Findings

Identification of a dynamic phase transition at T$_N$ = 103 K

Discovery of magnetic domain formation above and below T$_N$

Observation of distinct magnetic environments between 103 K and 230 K

Abstract

The magnetism of double perovskites is a complex phenomenon, determined from intra- or interatomic magnetic moment interactions, and strongly influenced by geometry. We take advantage of the complementary length and time scales of the muon spin rotation, relaxation and resonance ($\mu^+$SR) microscopic technique and bulk AC/DC magnetic susceptibility measurements to study the magnetic phases of the LaCaNiReO$_6$ double perovskite. As a result we are able to discern and report a newly found dynamic phase transition and the formation of magnetic domains below and above the known magnetic transition of this compound at T$_N$ = 103 K. $\mu^+$SR, serving as a local probe at crystallographic interstitial sites, reveals a transition from a metastable ferrimagnetic ordering below T = 103 K to a stable one below T = 30 K. The fast and slow collective dynamic state of this system are investigated. Between 103 K < T < 230 K, the following two magnetic environments appear, a dense spin region and a static-dilute spin region. The paramagnetic state is obtained only above T > 270 K. An evolution of the interaction between Ni and Re magnetic sublattices in this geometrically frustrated fcc perovskite structure, is revealed as a function of temperature and magnetic field, through the critical behaviour and thermal evolution of microscopic and macroscopic physical quantities.