The thermochemical behavior of some binary shape memory alloys by high temperature direct synthesis calorimetry
摘要:
The standard enthalpies of formation of some shape memory alloys have been measured by high temperature direct synthesis calorimetry at 1373 K. The following results (in kJ/mol of atoms) are reported: CoCr (-0.3 +/- 2.9); CuMn (-3.7 +/- 3.2); Cu3Sn (-10.4 +/- 3.1); Fe2Tb (-5.5 +/- 2.4); Fe2Dy (-1.6 +/- 2.9); Fe17Tb2 (-2.1 +/- 3.1); Fe17Dy2 (-5.3 +/- 1.7); FePd3 (-16.0 +/- 2.7); FePt (-23.0 +/- 1.9); FePt3 (-20.7 +/- 2.3); NiMn (-24.9 +/- 2.6); TiNi (-32.7 +/- 1.0); TiPd (-60.3 +/- 2.5). The results are compared with some earlier experimental values obtained by calorimetry and by EMF technique. They are also compared with predicted values on the basis of the semi empirical model of Miedema and co-workers and with ab initio calculations when available. We will also assess the available information regarding the structures of these alloys. (C) 2011 Elsevier B.V. All rights reserved.
Absorption spectrum of the trimer silver cluster <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" display="inline" overflow="scroll"><mml:mrow><mml:msubsup><mml:mrow><mml:mi mathvariant="normal">Ag</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msubsup></mml:mrow></mml:math> and metal nanoparticles in microemulsion
作者:Sudhir Kapoor、Ravi Joshi、Tulsi Mukherjee
DOI:10.1016/j.cplett.2004.08.080
日期:2004.10
Classical quantum simulation suggests the formation of Ag-3(2+) [Chem. Phys. Lett. 389 (2004) 150]. We present the effect of water pool radii on the transient absorption spectra of initial silver clusters. Experimental evidence for the formation of Ag-3(2+) in micro-emulsion system is reported for the first time. The surface plasmon absorption band of stable silver clusters obtained by bombardment of electron pulses in water-in-oil microemulsions showed absorption maximum at 405 nm. The transmission electron micrograph studies showed the presence of silver nanoparticles having an average size of 10 nm. (C) 2004 Elsevier B.V. All rights reserved.