Dynamical ground state in the XY pyrochlore Yb2GaSbO7

Abstract

The magnetic ground state of the pyrochlore Yb2GaSbO7 has not been established. The persistent spin fluctuations observed by muon spin-relaxation measurements at low temperatures have not been adequately explained for this material using existing theories for quantum magnetism. Here we report on the synthesis and characterisation of Yb2GaSbO7 to revisit the nature of the magnetic ground state. Through DC and AC magnetic susceptibility, heat capacity, and neutron scattering experiments, we observe evidence for a dynamical ground state that makes Yb2GaSbO7 a promising candidate for disorder-induced spin-liquid or spin-singlet behaviour. This state is quite fragile, being tuned to a splayed ferromagnet in a modest magnetic field μ0Hc ~ 1.5 T.

Spin liquid state in a rare-earth hyperkagome lattice

“…2 (b) in the temperature range 54 mK ≤ T ≤ 10 K. Below 2 K, the zero-field magnetic specific heat, C mag (T ) starts increasing and shows a broad maximum around 0.18 K, which indicates the presence of short-range spin correlations between Yb 3+ moments [28]. The presence of broad maximum around 0.18 K agrees well with the estimated CW temperature at low temperatures and it is consistent with general expectation for a quantum spin liquid candidate [58]. In finite applied magnetic fields, it is observed that the broad maximum shifts to higher temperatures with increased field which opens gap owing to Zeeman splitting of the lowest Kramers doublet state.…”

“…The calculated Landé g factor, g = 3.46 ± 0.02, from the low-temperature Curie-Weiss fit of magnetic susceptibility, is close to that obtained Landé g factor from Brillouin function fit of the magnetization isotherm. A similar value of powder average of Landé g factor is also observed in Yb based 3D pyrochlore system suggesting the single-ion properties of LYTO are expected to be similar to the pyrochlore system [58].…”

“…Fig. 1 (d) depicts the real part of ac susceptibility as a function of temperature down to 45 mK and it exhibits a broad maximum around 80 mK which suggests the short range interaction between Yb 3 + moments in LYTO [57][58][59]. Importantly, the absence of any frequency dependency of ac susceptibility strongly rules out glassy behavior of Yb 3+ spins in LYTO.…”

Traversing the pyrochlore stability diagram; microwave-assisted synthesis and discovery of mixed B-site Ln$_2$InSbO$_7$ family

“…Part of the historical hesitation behind the mixed Bsite pyrochlores comes from the negative connotation of "disorder" and its association with "dirty" samples [81]. Recently, however, there has been a surge of renewed interest in the mixed B-site pyrochlores [82][83][84][85][86][87], driven by the emerging picture of the profound effects that disorder can play on cooperative magnetic properties. Recent experimental studies on Pr 2 Zr 2 O 7 suggest the possibility that disorder may in fact provide a key route in the realization of both exotic, and possibly novel magnetic ground states [55,81].…”

“…Recent experimental studies on Pr 2 Zr 2 O 7 suggest the possibility that disorder may in fact provide a key route in the realization of both exotic, and possibly novel magnetic ground states [55,81]. The studies that do exist for mixed B-site pyrochlores are fascinating in their own right, and the most thorough investigations have indicated that the mixed Ga 3+ Sb 5+ compositions are remarkably similar to the Ln 2 Ti 2 O 7 titanates in both structure and properties [80,[82][83][84]. As such, we postulate that the richness of the Ln 2 B 2 O 7 phases may be mirrored in their mixed B-site counterparts, but with additional chemical degrees of freedom.…”