arXiv subjects

G. Apostolopoulos

Publications and source records attributed to G. Apostolopoulos.

3 recordsLinked to original sources

arXiv2023

On the use of SRIM for calculating arc-dpa exposure

We propose two methods for evaluating athermal recombination corrected (arc) displacement damage parameters in ion irradiations employing the computer code SRIM (Stopping and Range of Ions in Matter). The first method consists of post-processing the detailed SRIM output for all simulated damage events and re-calculating according to the arc damage model. In the second method, an approximate empirical formula is devised which gives the average displacements in the arc damage model as a function of the corresponding quantity according to the standard Norgett-Robinson-Torrens model, which is readily obtained from SRIM.

cond-mat.mtrl-sci↗

arXiv2016

On the analysis of stage I in the resistivity recovery of electron irradiated iron

The experimental results of Takaki et al. [1] on the stage I resistivity recovery of electron irradiated iron are analyzed using the analytical theory of diffusion annealing formulated by Simpson & Sossin [2] and Schroeder [3] taking into account the recent first-principles calculations of Fu et al. [4] regarding the mobility of interstitials. Excellent agreement between theory and experiment is obtained by a minimal set of adjustable parameters. The results show that the diffusion annealing equations can be successfully employed for the analysis of recovery experiments in iron.

cond-mat.mtrl-sci↗

arXiv2012

Mössbauer spectroscopy of short-range ordered Fe-Cr alloys

Short-range ordering (SRO) in Fe-Cr has been the subject of a number of recent experimental and theoretical investigations, as ordering effects are significant for the phase stability of this technologically important alloy. Recently, discrepancies regarding the SRO behavior of Fe-Cr have been reported between results obtained with Mössbauer spectroscopy and diffuse neutron scattering, respectively. As the methodology for reducing SRO parameters from Mössbauer spectra is indirect and relies on the determination of a large number of parameters, here a new method for directly connecting the Mössbauer effect with SRO is presented. The method is verified using synthetic spectra derived from Monte-Carlo simulated alloy structures with different SRO parameters and subsequently it is applied to experimental data obtained from Fe-Cr alloys. Agreement with diffuse neutron scattering is found at low Cr concentrations; however, some discrepancies still remain for more concentrated alloys and possible reasons for these are discussed.

cond-mat.mtrl-sci↗