P. Wodniecki's research while affiliated with Institute of Nuclear Physics and other places

... The PAC spectrum designated by 298 * K is taken at room temperature after the measurement at 1073 K quadrupole frequencies obtained for Zr 2 Ni 7 and Zr 7 Ni 10 phases in the temperature range 77-1073 K have been fitted with the following relationω Q (T ) = ω Q (0)[1 − αT ].( 3 )The fitted results give ω Q (0) = 65(1)Mrad/s (V zz = 7.3(2)×10 21 V/m 2 ), α = 3.1(3)×10 −4 K −1 for Zr 7 Ni 10 component. For the Zr 2 Ni 7 component, the results are ω Q (0) = 77(1) Mrad/s (V zz = 8.6(2)×10 21 V/m 2 ), α = 2.1(2)×10 −4 K −1 .The linear temperature dependence of quadrupole frequency was observed in many intermetallic compounds[21][22][23][24][25][26][27]. ...

... The PAC spectrum designated by 298 * K is taken at room temperature after the measurement at 1073 K quadrupole frequencies obtained for Zr 2 Ni 7 and Zr 7 Ni 10 phases in the temperature range 77-1073 K have been fitted with the following relationω Q (T ) = ω Q (0)[1 − αT ].( 3 )The fitted results give ω Q (0) = 65(1)Mrad/s (V zz = 7.3(2)×10 21 V/m 2 ), α = 3.1(3)×10 −4 K −1 for Zr 7 Ni 10 component. For the Zr 2 Ni 7 component, the results are ω Q (0) = 77(1) Mrad/s (V zz = 8.6(2)×10 21 V/m 2 ), α = 2.1(2)×10 −4 K −1 .The linear temperature dependence of quadrupole frequency was observed in many intermetallic compounds[21][22][23][24][25][26][27]. ...

... Hyperfine interaction techniques such as perturbed angular correlation (PAC) and Mössbauer spectroscopy can provide structural analysis of intermetallic compounds doped with very low concentrations of impurity (probe) atoms and often lead to definite conclusions on their lattice locations in polycrystalline materials [1][2][3]. In the last decade, a systematic study of the electric field gradients (EFG) of 181 Hf/ 181 Ta and 111 In/ 111 Cd probe nuclei in the full series of hafnium and zirconium aluminides has been carried out, intermetallic compounds which exhibit a large range of rather simple lattice structures [3][4][5][6][7][8][9][10][11]. Recently, successful attempts have been made for the compounds Zr 4 Al 3 and Hf 4 Al 3 to assign the hyperfine interaction parameters of 181 Hf/ 181 Ta probes to the possible Hf and Zr lattice sites [2] and even to distinguish among the lattice structures deduced from x-ray diffraction [12]. ...

... Hyperfine interaction techniques such as perturbed angular correlation (PAC) and Mössbauer spectroscopy can provide structural analysis of intermetallic compounds doped with very low concentrations of impurity (probe) atoms and often lead to definite conclusions on their lattice locations in polycrystalline materials [1][2][3]. In the last decade, a systematic study of the electric field gradients (EFG) of 181 Hf/ 181 Ta and 111 In/ 111 Cd probe nuclei in the full series of hafnium and zirconium aluminides has been carried out, intermetallic compounds which exhibit a large range of rather simple lattice structures [3][4][5][6][7][8][9][10][11]. Recently, successful attempts have been made for the compounds Zr 4 Al 3 and Hf 4 Al 3 to assign the hyperfine interaction parameters of 181 Hf/ 181 Ta probes to the possible Hf and Zr lattice sites [2] and even to distinguish among the lattice structures deduced from x-ray diffraction [12]. ...

... For most pure and impurity systems a T 3/ ' 2 dependence of EFG was found [10] and was understood as originating mainly from lattice vibrations and thermal lattice expansion [11]. There are, however, cases where a T 3/2 dependence is not observed [4, 12]. The deviations are not limited to transition metals, showing that they do not arise entirely from the local d-contributions. ...

... Sb. The intermetallic compound NiSb 2 has the marcasite (C18) structure [24], which exists below 616 8C in the miscibility range of 67.7 -68.7 at.% Sb. ...

... 7 The high energy density deposition by ion irradiations leads to the structural changes, transport mechanism, modifications of the surfaces, and the interfaces and also to the formation of new intermetallic phases at the interfaces in the case of thin films and multilayers. [8][9][10][11] In the case of cobalt thin films, the energy deposition by ion beam irradiation lead to a phase transition from hcp to fcc Co phase and also lead to significant changes in the magnetic anisotropy. Xe ion on 75 nm thick Co film changes the crystal structure of Co film from hcp to fcc. 12 Yan et al. observed the phase transitions from hcp-Co to the high temperature stabilized fcc structure in the case of immiscible Ag-Co system upon 200 keV Xe-ion ir-radiations at 300 K. 13 Mattei et al. showed the increase in hcp to fcc transition temperature dependent on the size of the cobalt nanoclusters obtained by ion implantation in silica. ...

... Available results suffer from simplifications in modeling, as the presence of concentration gradients was not taken into account for the determination of the diffusion coefficients. 3,22,23 In other cases, inadequate models were used for the determination of volume and grain boundary diffusion coefficients. 24 The rate controlling mechanisms (grain boundary or volume diffusion) are not properly discussed 24 and it is left unclear which type of diffusion coefficient was determined. ...

... In magnetic interaction, the magnetic dipole moment of the probe nucleus interacts with the internal/external magnetic field. Using this technique, several studies in Hf/Zr-Ni systems were carried out earlier to investigate their EFGs and magnetic properties [11][12][13][14][15][16][17]. Recently we have studied the structural properties of (Zr/Hf) 8 Ni 21 , (Zr/Hf) 7 Ni 10 using the PAC technique [18,19]. ...

... For the TiPd with lowest hafnium concentration measured with 181 Ta about 90% of the probe atoms exhibit EFG1, characterized by the quadrupole frequency ν Q1 = 312(2) MHz (η 1 = 0.19 (1)). The rest of the probes exhibit slightly larger EFG2 (ν 2 = 354(2) MHz) with larger asymmetry parameter (η 2 = 0.59 (3)) [15]. [16] for TiPd intermetallic compounds conrmed the assumption that the 111 Cd and 181 Ta substitutes mainly Ti atoms in the lattice ( Table I). ...