Reentrant superconductivity in the orthorhombic system (Tm1−xLux)RuB2

The boundaries between the paramagnetic, superconducting and magnetically ordered phases in the orthorhombic pseudoternary system (Tm_1?xLu_x)RuB₂ have been established by means of ac magnetic susceptibility measurements down to 1.2 K. Reentrant superconductivity occurs between x = 0.52 and x ? 0.68. The absence of coexistence between superconductivity and long range magnetic order in this region suggests a ferromagnetic-like nature of the magnetic state. The initial linear depression of superconducting transition temperature (T_c) gives a coupling constant value N(E_F)$\text{J}$² between conduction electrons and magnetic Tm³⁺ moments of 6.7 × 10^?4 eV-atom-states/ spin direction.     

Fourier transform infrared studies of inhibited autoxidation in cis-1,4-polybutadiene

The inhibited autoxidation of cis-1,4-polybutadiene (BR) was examined by Fourier transform infrared spectroscopy (FTIR) in the presence of three chain-breaking antioxidants: 2,6-di-tert-butyl-4-methylphenol (CA-1); 4,4′-methylene-bis-(2,6-di-tert-butylphenol) (CA-2) and N-phenyl-2-naphthylamine (CA-3). Weak interaction is detected between the phenolic OH and arylamine NH groups and the rubber unsaturation. These antioxidants terminate two or more kinetic chains per molecule and their mechanisms are described.     

Electron spin resonance on GdxMo6Se8 (x = 1.0 and 1.2)

Electron spin resonance of Gd³⁺ in Gd_xMo₆Se₈ (x = 1.0 and 1.2) has been measured in X-band and in K-band between 1.4 and 290 K. The results indicate that the conduction electron - Gd³⁺ spin exchange coupling constant is positive and equal to +0.011 eV, in agreement with previous determinations based on superconductivity and static magnetic susceptibility measurements.