Thermal history dependence of the crystal structure of Co fine particles

2005 ◽  
Vol 71 (2) ◽  
Author(s):  
X. Q. Zhao ◽  
S. Veintemillas-Verdaguer ◽  
O. Bomati-Miguel ◽  
M. P. Morales ◽  
H. B. Xu
Keyword(s):  
Crystal Structure ◽  
Thermal History ◽  
Fine Particles ◽  
History Dependence

Studies of copper selenide ultrafine particles by newly developed gas evaporation method

1990 ◽  
Vol 48 (4) ◽  
pp. 306-307
Author(s):  
Chihiro Kaito ◽  
Yoshio Saito
Keyword(s):  
Crystal Structure ◽  
Ultrafine Particles ◽  
Fine Particles ◽  
Production Method ◽  
Atmospheric Temperature ◽  
Copper Selenide ◽  
Quartz Boat ◽  
Selenium Vapor ◽  
Ar Gas ◽  
Ultra Fine Particles

The direct evaporation of metallic oxides or sulfides does not always given the same compounds with starting material, i.e. decomposition took place. Since the controll of the sulfur or selenium vapors was difficult, a similar production method for oxide particles could not be used for preparation of such compounds in spite of increasing interest in the fields of material science, astrophysics and mineralogy. In the present paper, copper metal was evaporated from a molybdenum silicide heater which was proposed by us to produce the ultra-fine particles in reactive gas as shown schematically in Figure 1. Typical smoke by this method in Ar gas at a pressure of 13 kPa is shown in Figure 2. Since the temperature at a location of a few mm below the heater, maintained at 1400° C , were a few hundred degrees centigrade, the selenium powder in a quartz boat was evaporated at atmospheric temperature just below the heater. The copper vapor that evaporated from the heater was mixed with the stream of selenium vapor,and selenide was formed near the boat. If then condensed by rapid cooling due to the collision with inert gas, thus forming smoke similar to that from the metallic sulfide formation. Particles were collected and studied by a Hitachi H-800 electron microscope.Figure 3 shows typical EM images of the produced copper selenide particles. The morphology was different by the crystal structure, i.e. round shaped plate (CuSe;hexagona1 a=0.39,C=l.723 nm) ,definite shaped p1 ate(Cu5Se4;Orthorhombic;a=0.8227 , b=1.1982 , c=0.641 nm) and a tetrahedron(Cu1.8Se; cubic a=0.5739 nm). In the case of compound ultrafine particles there have been no observation for the particles of the tetrahedron shape. Since the crystal structure of Cu1.8Se is the anti-f1uorite structure, there has no polarity.

Interplay of crystallization and liquid–liquid phase separation in polyolefin blends: A thermal history dependence study

Polymer ◽  
2007 ◽  
Vol 48 (14) ◽  
pp. 4226-4234 ◽  
Author(s):  
Katsumi Shimizu ◽  
Howard Wang ◽  
Go Matsuba ◽  
Zhigang Wang ◽  
Hongdoo Kim ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Thermal History ◽  
Liquid Phase Separation ◽  
History Dependence ◽  
Polyolefin Blends ◽  
Liquid Liquid Phase Separation

Thermal history dependence of indentation induced densification in an aluminosilicate glass

2016 ◽  
Vol 445-446 ◽  
pp. 34-39 ◽  
Author(s):  
Simon Striepe ◽  
Joachim Deubener ◽  
Marcel Potuzak ◽  
Morten M. Smedskjaer ◽  
Anja Matthias
Keyword(s):  
Thermal History ◽  
Aluminosilicate Glass ◽  
History Dependence

Temperature and thermal history dependence of the microstructure in bituminous materials

2013 ◽  
Vol 49 (8) ◽  
pp. 1964-1974 ◽  
Author(s):  
S.N. Nahar ◽  
A.J.M. Schmets ◽  
A. Scarpas ◽  
G. Schitter
Keyword(s):  
Thermal History ◽  
History Dependence ◽  
Bituminous Materials
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