Superconductivity and magnetic ordering in the mixed ternary ErxY1−xRh1.1Sn3.6 system

The superconducting transition temperature Tc as well as the magnetic ordering temperature Tm have been determined in the mixed ternary compound ErxY1−xRh1.1Sn3.6 as a function of the Er concentration. Tc decreases from 3.13 K for YRh1.1Sn3.6 to 1.1K for ErRh1.1Sn3.6. Reentrant superconductivity has been found for x > 0.6.\ud \ud The application of the models of Abrikosov and Gorkov, Maekawa and Tachiki, and Roshen and Ruvalds to this system is discussed. Tc as function of the concentration x is best described by the model of Roshen and Ruvalds assuming a ferromagnetic interaction between the spins. The parameter I2N(0), arising from electron spin, is found to be 0.088 K. The ferromagnetic ordering temperature dependence is described by the theory of Oguchi and Ono, using an effective coordination number z = 6 and an exchange constant of J′ = 0.30 K

Spin glass behaviour in the rare earth ternary stannide HoRh1.2Sn3.9

Dynamic susceptibility measurements on HoRh1.2Sn3.9 have been performed in the vicinity of its magnetic transition at TM = 1.7 K. χ'(T) exhibits a cusp-like peak, which is substantially depressed when an external field of a few mT is applied. Below TM a strong frequency dependence of the susceptibility is found. The results are very similar to those of classical spin glass behaviour for HoRh1.2Sn3.9. Results on other phase II ternary stannides as, e.g., the reentrant magnetic superconductor ErRh1.1Sn3.6 may be interpreted likewise

Nail Involvement in Alopecia Areata: A Questionnaire-based Survey on Clinical Signs, Impact on Quality of Life and Review of the Literature

Contains fulltext : 190317.pdf (publisher's version ) (Open Access)Alopecia areata (AA) is an immune-mediated disease causing temporary or permanent hair loss. Up to 46% of patients with AA also have nail involvement. The aim of this study was to determine the presence, types, and clinical implications of nail changes in patients with AA. This questionnaire-based survey evaluated 256 patients with AA. General demographic variables, specific nail changes, nail-related quality of life (QoL), and treatment history and need were evaluated. Prevalence of nail involvement in AA was 64.1%. The specific nail signs reported most frequently were pitting (29.7%, p = 0.008) and trachyonychia (18.0%). Red spots on the lunula were less frequent (5.1%), but very specific for severe AA. Nail-related QoL was only minimally affected by nail changes. In conclusion, nail involvement is common in patients with AA and presents mostly with pitting and trachyonychia. The presence of these nail changes reflects the severity of the disease, with red spots on the lunula as a predictor for severe alopecia

Superconducting and magnetic phase transitions in RExY1-xRh1.1Sn3.6 (RE=Er, Ho)

The superconducting (Tc and magnetic ordering (Tm) critical temperatures in RExY1-xRh1.1Sn3.6 (RE = Er, Ho) have been determined by magnetic measurements. For RE = Er superconductivity appears for any value of x, and reentry to a magnetically ordered state for x ≥ 0.6, while for RE = Ho the compound becomes either superconducting or magnetically ordered, and is expected to remain paramagnetic for x near 0.5. Theories of Abrikosov-Gorkov and Roshen-Ruvalds are used to explain Tc(x) , leading to I2N(0)G=0.23 K and 0.8 K for Er and Ho respectively. Comparison of Tm(x) with the theory of Oguchi-Obokata gives respectively J = 0.30 K and 0.96, using a Heisenberg model with z = 6