Short-range magnetic interactions in the spin-ice compoundHo2Ti2O

Magnetothermal study of a Dy-stuffed spin ice:Dy2(DyxTi2−x)Ueland1, Lau2, Freitas3 et al. 2008Phys. Rev. B16140View full textAdd to dashboardCite

“…4a. We find that [33] and with the observed residual entropy [17,35]. The finite susceptibility as T ~ 0 in Dy SSI, however, indicates that some spins remain fluctuating down to the lowest temperatures measured -a somewhat curious result since stuffing in more Dy ions yields a higher density of spins and stronger average spin-spin interactions.…”

Nonmonotonic residual entropy in diluted spin ice: A comparison between Monte Carlo simulations of diluted dipolar spin ice models and experimental results

“…As is well known, a Pauling residual entropy is generically found in undiluted spin ice materials, 9,10,13,14,24,25 See, however, Ref. [26] where no residual Pauling entropy plateau is found in Dy 2 Ti 2 O 7 if extraordinary long relaxation time scales of several days is afforded below a temperature of order of 0.4 K. We return to this issue later in this Introduction.…”

“…Ho-based samples were pressed directly into pellets and the magnetic specific heat was obtained after subtracting both the phonon and the large Ho nuclear Schottky anomaly contribution. 24,28 The data, C m (T )/T , integrated from T 0 (x) = 0.4 ± 0.1 K, depending on the lowest temperature T 0 (x) experimentally accessed for a given concentration x, up to a ('high') temperature T ≫ T peak (x), was used to determine the residual low-temperature entropy, S res (T 0 ). As discussed in the Introduction, the residual entropy reported in Ref.…”

Ambient-pressure bulk superconductivity deep in the magnetic state ofCeRhIn5

“…1, the specific heat of CeRhIn 5 is characterized by a dramatic transition into the antiferromagnetic state at 3.8 K, as evidenced by the sharp anomaly in C(T ). Below T N , C(T ) has been previously characterized as composed of a standard electronic contribution C e (T ) = γT with γ = 56 mJ/mol-K 2 , in line with the universal Kadowaki-Woods ratio, 12 and a magnetic contribution C m (T ), which itself shows evidence of a gapped desity-wave-like state with gap magnitude of ∼ 8 K. 10 Here we reproduce the same results, but focus on the properties far below T N . In this regime, the total specific heat can be described by the sum of several standard contributions:…”

“…6 Furthermore, the application of magnetic field exposes additional anomalies, including a first-order superconductor to normal state transition, 2,7 and a magnetic quantum critical point which coincides with the upper critical field H c2 . 8 CeRhIn 5 , on the other hand, is a wellcharacterized 10,11,12 antiferromagnet at ambient conditions with a Néel temperature T N = 3.8 K that is gradually suppressed upon application of pressure 11,13,14,15 or Co substitution 16,17 to reveal a superconducting state that is widely thought 18 to resemble that found in CeCoIn 5 . This tuning is considered to be strongly tied to the nature of Ce f -electron states, since both theoretical 19 and experimental 19,20 evidence points to a localized f -electron scenario for CeRhIn 5 and a delocalized one for CeCoIn 5 .…”