| 1 | Author
| Mohamed Yalpani, WernerE. Klotzbücher | Requires cookie* | | Title
| Transformations in Thin Solid Layers: The Reversible Polymerization-Depolymerization of 2,6-Di-n-propyl- l,3>5,7-tetraoxa-2,6-dibora-4,8-octalindiones at Low Temperatures  | | | Abstract
| The course of Aggregation of molecules of the title compound (lb) through different, spectro-scopically discernible and chemically identifiable forms of associations could be followed by matrix isolation and thin film infrared and UV-visible spectroscopy. It was found that molecules of lb in thin films form clusters which at low temperatures interact weakly, probably through the carbonyl oxygens of one and the boron atoms of the neighbouring molecules. On warming to 260 K this association gradually takes the form of more defined chelate bonds, probably with ordered three-dimensional intermolecular structures. Above this temperature spontaneous for-mation of crystallites of the previously reported 'hot' and 'cold' modifications was observed. Studies with films of varying thickness indicate an interdependence of crystallite size and lattice energies. | | |
Reference
| Z. Naturforsch. 40b, 222—228 (1985); received September 24 1984 | | |
Published
| 1985 | | |
Keywords
| Solid State Reaction, Matrix Isolation, Aggregation, Phase Transformation, Microcrystals | | |
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| default:Reihe_B/40/ZNB-1985-40b-0222.pdf | | | Identifier
| ZNB-1985-40b-0222 | | | Volume
| 40 | |
2 | Author
| M. Sorescu, E. T. Knobbe | Requires cookie* | | Title
| Mössbauer Spectroscopy Evidence for Phase Selectivity in Excimer Laser Induced Amorphization of Thermally Annealed FeCoBSi Metallic Glass  | | | Abstract
| Pulsed excimer laser irradiation effects (/. = 308 nm, T = 10 ns, w = 3 J/cm 2 , N = 2 laser pulses/ spot, repetition rate 1 Hz) on the magnetic properties and phase composition of thermally annealed Fe 66 Co 18 B 15 Si 1 metallic glass have been studied by transmission and conversion electron Möss-bauer spectroscopy (CEMS). Radiation-driven surface modifications were examined by scanning electron microscopy (SEM). Excimer laser induced amorphization was observed in partially crystal-lized Fe 66 Co 18 B 15 Si 1 samples (7" A = 648 K, r A = 1 hour) and was found to be accompanied by the development of laser-induced magnetic anisotropy. In totally crystallized Fe^Co^B^Si! speci-mens (T A = 723 K, = 1 hour), the effect of excimer laser induced amorphization exhibited phase selectivity with respect to the crystalline components of the alloy system. When compared to bulk data, a different behavior of the surface magnetic texture and relative abundance of alloy phases was observed. The laser-induced phase transformation of thermally annealed Fe 66 Co 18 B 15 Si 1 specimens was shown to consist of partial amorphization and surface oxidation of the irradiated material. | | |
Reference
| Z. Naturforsch. 51a, 389—395 (1996); received February 3 1996 | | |
Published
| 1996 | | |
Keywords
| Metallic glasses, Laser processing, Phase transformations, Magnetic properties, Möss-bauer spectroscopy | | |
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| default:Reihe_A/51/ZNA-1996-51a-0389.pdf | | | Identifier
| ZNA-1996-51a-0389 | | | Volume
| 51 | |
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