Quasistatic magnetism in the breathing pyrochlore antiferromagnets LiGa1−xInxCr4O8 (x=0.2, 0.5)

Abstract

We report magnetic susceptibility, high-field magnetization, muon spin relaxation, and electron spin resonance measurements of the breathing pyrochlore antiferromagnets LiGa(1-xI)n(x)Cr(4)O(8) (x = 0.2, 0.5). Unlike the previously proposed spin-glass-like phase for 0.1 . 1 < x < 0.75, we find no signature for spin glassiness and phase segregation in both the x = 0.2 and 0.5 compounds. Instead, we identify a two-step magnetic transition with a partial spin freezing at T * = 12 K (x = 0.2) and 9 K (x x = 0.5) followed by quasistatic order at T (m) = 6 K (x = 0.2) . 2) and 3 K for (x = 0.5). . 5). In addition, for T (m) < T < T * , we observe evidence of a competition between fast and slow spin dynamics, suggesting a thermal and temporal distribution of spin correlations. Our findings underscore the possibility of realizing novel magnetic phases by tuning bond alternation and introducing bond disorder through chemical substitution.