Interaction of Neutrons With Molecules

Abstract

The Phillips and Van Vechten theory was applied to aluminum, gallium and indium pnictides (AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs and InSb). The values of the homopolar gap, ionic gap and Penn gap were evaluated for these binary semiconductors. The derived values of E h and E p were found to be in good agreement with the values obtained from the Phillips model and the Penn model. Electronic polarizability was investigated using the Chemla relation and the values were found to be in agreement with the results obtained from the Clausius-Mossotti relation. The Phillips ionicity ( f i ) was evaluated and the obtained values were compared with the values obtained from the Tubbs model and the Pauling ionicity model. The evaluated values of various ionicities were used to determine the microhardness (H), cohesive energy or total energy (E) and bulk modulus (B) of these materials. The values of these parameters thus obtained are in good agreement with previously reported experimental data and theoretical findings. PACS numbers: 71.15.Nc, 71.55.Eq 2. Theory Phillips [10, 11] and Van Vechten [12] have defined the Penn gap E p , homopolar gap E h and ionic gap E c for an elemental

Optical and Magnetic Studies of Tripositive Thulium in Octahydrated Sulfate Crystals

“…The effective susceptibility XE along an arbitrary direction through the crystal is l3 (8) where COsOl and COs02 are the direction cosines of their respective susceptibilities along the direction defined bYXE. Figure 15 shows the experimental orientation of single-crystal Tm2 (S04) 3' 8H20 used for the anisotropy measurement.…”

“…Olsen and Gruber4 have recently confirmed this and supported Harrop's6 earlier prediction based on a crystal field analysis of isostructural rare earth chlorides. Since the space group symmetry of both the hexahydrated chloride and the octahydrated sulfate is C 2h /, 8 one is inclined to expect that the Tm H ions in both salts will display similar optical characteristics. Therefore, it is not too surprising that we have found the ground state in Tm2(S04)s"SH20 to also be composed of nearly de-generate singlets.…”

Resistive reconnection

“…In addition, it has been proposed that small magnetic islands are responsible for the anomalous electron heat transport observed in tokamaks. The magnitude of this effect was examined by Boozer and White (1982) and White (1984) and the self-consistent effect of the islands on the current profile by Ivanov (1983).…”

Ultrafast domain wall motion in ferrimagnets induced by magnetic anisotropy gradient

“…The last term is the interfacial DM interaction with D > 0 and ey is the unit vector in the y direction. To obtain an more explicit expression of the Lagrangian density, we replace m with m = s ṅ  n, 36,37 and…”