A Relation between the Hyperfine Magnetic and Electronic Structure and the Passivability of the Heat Treated Fe
23% Cr Alloy
O. V. Kasparova*, Yu. V. Baldokhin**, and A. S. Solomatin**
* Karpov Institute of Physical Chemistry, ul. Vorontsovo Pole 10, Moscow, Russia
** Semenov Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina 4, Moscow, Russia
Received February 8, 2005
Abstract — The effect of heat treatment conditions (quenching and tempering at 475°C for 200 h or at 650°C for 10 h) on the hyperfine magnetic structure, electron density distribution at 57Fe nuclei, and passivability of Fe–23% Cr alloys in either a highly pure state or with a heightened content of impurity elements is studied with the use of Mössbauer 
-resonance spectroscopy combined with voltammetric measurements in a 1mol/lHClO4+ 0.25 mol/l NaCl solution at room temperature. Mössbauer spectra are processed (decomposed in three subspectra) with the help of Normos computer program, and the following parameters are estimated: the effective magnetic field intensity Heff (kOe); the half-width of the first subspectrum peak 
(mm/s); the first-to-third (W13) and second-to-third (W23) ratios of the subspectrum peaks; the isomeric (chemical) shift 
(mm/s) with respect to 
-Fe; the quadrupole electric splitting 
eq (mm/s); and the area part S (%) of the hyperfine structure subspectrum in the summary spectrum. Hyperfine magnetic structure and electron density distribution at iron nuclei are found to change depending on the alloy purity and heat-treatment conditions. The 
spectroscopy data are considered in relation to the passivating characteristics of the alloy.
-resonance spectroscopy combined with voltammetric measurements in a 1mol/lHClO4+ 0.25 mol/l NaCl solution at room temperature. Mössbauer spectra are processed (decomposed in three subspectra) with the help of Normos computer program, and the following parameters are estimated: the effective magnetic field intensity Heff (kOe); the half-width of the first subspectrum peak (mm/s); the first-to-third (W13) and second-to-third (W23) ratios of the subspectrum peaks; the isomeric (chemical) shift (mm/s) with respect to -Fe; the quadrupole electric splitting eq (mm/s); and the area part S (%) of the hyperfine structure subspectrum in the summary spectrum. Hyperfine magnetic structure and electron density distribution at iron nuclei are found to change depending on the alloy purity and heat-treatment conditions. The spectroscopy data are considered in relation to the passivating characteristics of the alloy.