High field (up to 5 T) magnetization measurements were performed on both bulk and field-aligned powder samples of RNi2B2C (R=Dy, Ho) magnetic superconductors. For Tc=3.8 K, a DyNi2B2C superconductor with antiferromagnetic Néel temperature TN of 10-11 K, and anomalous field-induced weak-ferromagnetic transitions were observed above the superconducting upper critical field Hc2(2 K) of 1.75 kG. The aligned powders show distinct hysteresis characteristics for both fields applied parallel and perpendicular to the tetragonal basal plane. For Tc=7.8 K, HoNi2B2C has an incommensurate magnetic ordering temperature Tm of 6 K and TN of 5.2 K. Anomalous field-induced weak-ferromagnetic transitions were also observed below TN. No hysteresis can be detected for TN<T<Tm.
ASJC Scopus subject areas
- 物理與天文學 (全部)