摘要:

AbstractThe single crystals from the series of Re1‐xBaxMnO3solid solutions (Re = Pr, Nd) were prepared by the flux growth from the melt containing 0.41 BaO — 0.18 BaF2— 0.41 B2O3. as the flux constituents. The conditions of the growth, in particular the liquidus curves of the relevant pseudobinary systems, were determined by the high‐temperature microscope technique. The prepared crystals were characterized by X‐ray and chemical

ISSN:0232-1300    

DOI:10.1002/crat.2170190202

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractThe results of an investigation of the growth of potassium bichromate crystals at the boiling point, and their habit and surface micromorphology are reported.

ISSN:0232-1300    

DOI:10.1002/crat.2170190203

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractMicroscopic and flotation density investigations have been performed of unmixing in equimolar single crystals of NaCl‐KCl at elevated temperatures. The surface nucleation is found to be characteristic of the decomposition process. The two‐phase regions formed at the surface grow inward at a constant linear rate. The activation energy for the movement of the decomposition front is 0.9 eV at 180 to 260°C. The decomposition is anisotropic,being the fastest unmixing direction. The decomposition zones nucleated on air bubbles inside the crystal tend to acquire a cube‐lik

ISSN:0232-1300    

DOI:10.1002/crat.2170190204

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractAn etchant capable of revealing the sites of dislocations in the flux‐grown crystals of BaMoO4has been established. Using this etchant (HNO3), effect of etching time, acid concentration and temperature on the selective etch rate is demonstrated. It is established that the process of dissolution in unstirred HNO2solutions is one of the diffusion rate controlled; an empirical equation governing the kinetics has been suggeste

ISSN:0232-1300    

DOI:10.1002/crat.2170190205

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractThermoluminescence (TL) glow curves were recorded in KBr, KI and in different compositions of KBrxI1‐xmixed crystals at LNT. For this a cryostat has been designed and fabricated. The glow peaks observed in these crystals have been attributed to differnent colour center

ISSN:0232-1300    

DOI:10.1002/crat.2170190206

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractGlow curves of the thermally pretreated NaCl:Ca crystals are recorded and are found to be complex in nature. The complex glow curve is analysed using thermal cleaning technique and the trap parameters are calculated by various methods. The glow peaks have been tentatively attributed to impurity and various types of colour centers.

ISSN:0232-1300    

DOI:10.1002/crat.2170190207

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractThe effect of growth conditions on the line broadening in low temperature luminescence spectra of pyrene‐doped biphenyl single crystals in investigated. It has been shown that the crystals, grown by plate sublimation technique, possess the minimal linewidth. Various possible mechanisms of line broadening are discusse

ISSN:0232-1300    

DOI:10.1002/crat.2170190208

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractThe effects of various materials parameters on hot deformabilityfof AISI M2 high speed steel are studied in a complex way. These studies revealed beside other parameters (e.g. carbides) a strong correlation between some impurities (S, Sn) andf, determined by hot deformability tests. The correlation betweenfand the P content prooved to be weaker. The paper is devoted to impurity effects. The composition and impurities of the samples and their isolated carbide phases have been determined by chemical analysis. In situ AES fractography and SEM were applied to study the fracture surfaces. The main results are: The S concentration of the fracture surfaces exhibits a correlation with the bulk content. Strong enrichment of S and P within a thin (1–3 nm) surface layer was revealed by AES in‐depth profiling, showing also carbide phases. In the temperature range ‐150°C — +250°C no grain boundary fracture was observed, fracture was ductile and void type. The fracture path is determined by carbides, being the sites of S and P e

ISSN:0232-1300    

DOI:10.1002/crat.2170190209

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractUnder the assumption that a dislocation decorated by impurities can be described as a macroscopic inhomogeneity the radial distribution of the flux of photons around a dislocation is calculated, where the internal absorption of the luminescence is taken into account in addition to the effect of the surface. The theoretical results are used to compute simulated images for different values of the radiative lifetime inside the dislocation region.

ISSN:0232-1300    

DOI:10.1002/crat.2170190210

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractIn the present paper a quite general approach is proposed for the problem of the formation of the prefered orientations (i.e. of the texture). The rotation field is considered by the present authors as the most general variable which describes completely the texture formation process. The proposed continuity equation transforms immediately the rotation field to the texture function (Orientation distribution function). The presented formatlism is illustrated by a few f.c.c. rolling textures.

ISSN:0232-1300    

DOI:10.1002/crat.2170190211

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY