31 research outputs found
Basal plane dislocation reduction for 8° off-cut, 4H-SiC using in situ variable temperature growth interruptions
Exploiting Phonon‐Resonant Near‐Field Interaction for the Nanoscale Investigation of Extended Defects
An E and C analysis of donor numbers and Soret band shifts in adducts of zinc tetraphenylporphine
Post-irradiation formation of Si-SiO2 interface states in a hydrogen atmosphere at room temperature
Studies of a polymeric chromium phosphinate: structure and static magnetic properties
The semicrystalline polymer, poly(chromium bismethylphenyldioctyl-phosphinate), PCrP-C, contains S=3/2 chromium ions coupled by Heisenberg antiferromagnetic exchange (J/k=−2.5 K) along the linear molecule. We present susceptibility and specific-heat data on pressed sheet samples. X-ray diffraction shows that there is preferential alignment of the molecules in the plane of the sheets, and allows an analysis of the resulting magnetic anisotropy. There is an easy plane perpendicular to the molecular axis and the anisotropy parameter (D/k≃−0.03 K) is such that a crossover from Heisenberg to XY behavior is observed as the temperature is lowered. There is no evidence for three-dimensional ordering above 20 mK. The effect of an applied magnetic field is to induce a flopped spin alignment in the one-dimensional short-range-ordered regime. We present a calculation, based on a transfer-matrix technique to include both magnetic field and anisotropy within a classical Heisenberg model, giving good semiquantitative agreement with the experimental data