A positron 1D-ACAR spectrometer for the study of 60Co containing materials

Gröne, R.; Haščík, Ján; Slugeň, V.; Lipka, Roman; Pietrzyk, P.; Vitázek, K.

doi:10.1016/s0168-583x(97)00212-7

Cited by 6 publications

(2 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…positron trapping by structural defects is not observed. In [16], E v in TiNi was determined by PAS according to the changing S-parameter the one-dimensional angular correlation of annihilation radiation (1D-ACAR) [19] at heating and cooling stages. S-parameter was defined as ratio of low-momentum area of 1D-ACAR to the total area.…”

Section: Vacancy Formation Energy In Titanium Nickelidmentioning

confidence: 99%

Formation of vacancy-type defects in titanium nickelide

Батурин

Лотков

Гришков

et al. 2015

MATEC Web of Conferences

View full text Add to dashboard Cite

Abstract. In this report we briefly review the current state-of-the-art and challenges in determining point defect properties from first-principles calculations as well as from experimental measurements in titanium nickelid. Based on the vacancy formation energy and the activation energy for vacancy migration in TiNi, vacancy mediated diffusion mechanism was examined. The influence of vacancies and antisite defects on the TiNi structural phase transition has been described. IntroducingInvestigating diffusion processes in titanium nickelid alloys sharpened several issues on types and characteristic features of point defects. In the publication of Bastin and Riek [1] it was established that the chemical diffusion coefficient in TiNi is determined by Ni diffusion, and the activation energy for diffusion is too small (~1.4 eV) compared to other B2 intermetallic compounds. Investigating Ni diffusion in relation to pressure [2] showed that activation volume of diffusion Ni in TiNi within experimental error is equals zero. This could imply that diffusion mechanism is interstitial mediated or that there are structural vacancies in the intermetallic compound. Diffusion mechanism in TiNi is a particular case to explain the common diffusion mechanism in B2 intermetallic compounds. As discussion of the diffusion mechanism in B2 intermetallic, causes disputes [3][4][5], research of point defects in TiNi is relevant. Besides, some authors [6][7][8][9] state that point defects configuration of a B2 phase can play an important role in nucleation and growth processes of martensitic phase. Vacancy formation energy in titanium nickelidIn AB compounds with B2 structure interatomic potentials of identical atoms AA and BB have distinct dependency on the distance between identical atoms in given coordination sphere; further, interatomic potentials of these identical atoms also have a different potential well [9]. This results in the fact that the vacancy formation energy (E v ) on the different atomic sublattices is non-identical, which, in its turn, could be revealed in some B2 compounds by the positron annihilation spectroscopy (PAS) method [10].Presently, investigations in measurement the vacancy formation energy in a series of intermetallic compounds In the reference well-annealed state average positron lifetime corresponds to a delocalized positron state, i.e. the vacancy concentration in a sample lower than the PAS method threshold limit. Further, when heating the a Corresponding author: abat@ispms.tsc.ru

show abstract

Section: Vacancy Formation Energy In Titanium Nickelidmentioning

confidence: 99%

Formation of vacancy-type defects in titanium nickelide

Батурин

Лотков

Гришков

et al. 2015

MATEC Web of Conferences

View full text Add to dashboard Cite

show abstract

“…New Coincidence Doppler Broadening setup was developed and constructed at the Slovak University of Technology (STU). After 1D ACAR (1 Dimensional Angular Correlation positron Annihilation Radiation) [5] and PALS (Positron Annihilation Lifetime Spectroscopy) setup it is a third Positron Annihilation measurement system permanently in use in our laboratory. Based on knowledge of previous works [1,2,3], replacing multi-parameter MCA by DAQ was realized in our setup in the form that the signal shaping tasks are performed digitally by software in a PC.…”

Section: Introductionmentioning

confidence: 99%

Software for Digital Coincidence Doppler Broadening Setup

Petriska

Sabelová

Slugeň

et al. 2012

MSF

View full text Add to dashboard Cite

An advanced digital measurement system for Coincidence Doppler broadening (CDB) technique is presented. Traditional CDB setups are based on shaping amplifiers and multi parameter multi-channel analyzers (MCA). We replaced them by 14-bit data acquisition card (DAQ). Replacing multi-parameter MCA by DAQ was realized also by several groups before, but in our setup the signal shaping tasks are performed digitally by software in a personal computer. Signals from high purity (HP) Ge detectors are sampled at preamplifier outputs. Pulse shaping is realized by a trapezoidal filter.

show abstract