Effect of rare-earth metals on the properties of chromized coatings deposited underconditions of self-propagating high-temperature synthesis

1998 ◽  
Vol 40 (3) ◽  
pp. 126-128
Author(s):  
B. P. Sereda
2012 ◽  
Vol 488-489 ◽  
pp. 442-446 ◽  
Author(s):  
Taschaporn Sathaporn ◽  
Sutham Niyomwas

The Eu2+ doped barium aluminate (BaAl2O4:Eu2+) and strontium aluminate (SrAl2O4:Eu2+) with high brightness were synthesized by self-propagating high temperature synthesis (SHS) method. The influence of doping rare earth ions (Eu2+) on the luminescence of MAl2O4:Eu2+ were described in this study. The reactions were carried out in a SHS reactor under static argon gas at a pressure of 0.5 MPa. The morphologies and the phase structures of the products have been characterized by X-ray diffraction (XRD) and scanning electron microscope technique (SEM). The emission spectra of the products have been measured by an Ocean optics spectrometer at room temperature. Broad band UV excited luminescence was observed for BaAl2O4:Eu2+ and SrAl2O4:Eu2+ in the green region peak at λmax = 501 nm and 523 nm, respectively. The optimum Eu2+ doping ratio were 10.5 mol% and 6 mol% for BaAl2O4:Eu2+ and SrAl2O4:Eu2+, respectively


2010 ◽  
Vol 25 (4) ◽  
pp. 718-727 ◽  
Author(s):  
Joel P. McDonald ◽  
Mark A. Rodriguez ◽  
Eric D. Jones ◽  
David P. Adams

Several binary intermetallic compounds—each containing a rare-earth (RE) element paired with a transition metal (TM)—were prepared by self-propagating, high-temperature synthesis (SHS). Thin multilayers, composed of alternating Sc or Y (RE element) and Ag, Cu, or Au (TM), were first deposited by direct current magnetron sputtering. Once the initially distinct layers were stimulated and caused to mix, exothermic reactions propagated to completion. X-ray diffraction revealed that Sc/Au, Sc/Cu, Y/Au, and Y/Cu multilayers react in vacuum to form single-phase, cubic B2 structures. Multilayers containing Ag and a RE metal formed cubic B2 (RE)Ag and a minority (RE)Ag2 phase. The influence of an oxygen-containing environment on the reaction dynamics and the formation of phase were investigated, providing evidence for the participation of secondary combustion reactions during metal-metal SHS. High-speed photography demonstrated reaction propagation speeds that ranged from 0.1–40.0 m/s (dependent on material system and foil design). Both steady and spin-like reaction modes were observed.


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