TY  - JOUR
AU  - Cekić, Božidar Đ.
AU  - Umićević, Ana
AU  - Ivanovski, Valentin N.
AU  - Hu, Rongwei
AU  - Petrovic, Cedomir
AU  - David, Bohumil
AU  - Barudžija, Tanja
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4925
AB  - The perturbed angular correlation method was employed to study the temperature dependence of electric field gradients at the Ta-181 probe in the polycrystalline Hf2Ni7 compound. The temperature evolution of the sample content was measured using high-temperature X-ray diffraction. To check the magnetic order of the sample, magnetization measurements and additional perturbed angular correlation measurements with externally applied magnetic field were performed. All obtained spectra showed no evidence of magnetic order of the Hf2Ni7 phase. Within the experimental resolution of the apparatus, the measured electric field gradients at Ta-181 probe for the two inequivalent Hf-181/Ta-181 sites in the Hf2Ni7 compound appeared as one in the range of 78-944 K. A single quadrupole interaction implies that the electric field gradients at the two Hf sites must be quite similar. At 293 K, the measured quadrupole interaction parameters are v(Q) = 433(1) MHz and eta = 0.300(4). An increase of the quadrupole frequency and a gradual rising of the asymmetry parameter were observed with increasing temperature. The high-temperature X-ray diffraction indicated a build up of HfO2 above 693 K.
T2  - Nuclear technology and radiation protection
T1  - Perturbed Angular Correlation Investigation of the Electric Field Gradient At Ta-181 Probe in the Hf2ni7 Compound
VL  - 27
IS  - 2
SP  - 95
EP  - 102
DO  - 10.2298/NTRP1202095C
ER  - 

@article{
author = "Cekić, Božidar Đ. and Umićević, Ana and Ivanovski, Valentin N. and Hu, Rongwei and Petrovic, Cedomir and David, Bohumil and Barudžija, Tanja",
year = "2012",
abstract = "The perturbed angular correlation method was employed to study the temperature dependence of electric field gradients at the Ta-181 probe in the polycrystalline Hf2Ni7 compound. The temperature evolution of the sample content was measured using high-temperature X-ray diffraction. To check the magnetic order of the sample, magnetization measurements and additional perturbed angular correlation measurements with externally applied magnetic field were performed. All obtained spectra showed no evidence of magnetic order of the Hf2Ni7 phase. Within the experimental resolution of the apparatus, the measured electric field gradients at Ta-181 probe for the two inequivalent Hf-181/Ta-181 sites in the Hf2Ni7 compound appeared as one in the range of 78-944 K. A single quadrupole interaction implies that the electric field gradients at the two Hf sites must be quite similar. At 293 K, the measured quadrupole interaction parameters are v(Q) = 433(1) MHz and eta = 0.300(4). An increase of the quadrupole frequency and a gradual rising of the asymmetry parameter were observed with increasing temperature. The high-temperature X-ray diffraction indicated a build up of HfO2 above 693 K.",
journal = "Nuclear technology and radiation protection",
title = "Perturbed Angular Correlation Investigation of the Electric Field Gradient At Ta-181 Probe in the Hf2ni7 Compound",
volume = "27",
number = "2",
pages = "95-102",
doi = "10.2298/NTRP1202095C"
}

Cekić, B. Đ., Umićević, A., Ivanovski, V. N., Hu, R., Petrovic, C., David, B.,& Barudžija, T.. (2012). Perturbed Angular Correlation Investigation of the Electric Field Gradient At Ta-181 Probe in the Hf2ni7 Compound. in Nuclear technology and radiation protection, 27(2), 95-102.
https://doi.org/10.2298/NTRP1202095C

Cekić BĐ, Umićević A, Ivanovski VN, Hu R, Petrovic C, David B, Barudžija T. Perturbed Angular Correlation Investigation of the Electric Field Gradient At Ta-181 Probe in the Hf2ni7 Compound. in Nuclear technology and radiation protection. 2012;27(2):95-102.
doi:10.2298/NTRP1202095C .

Cekić, Božidar Đ., Umićević, Ana, Ivanovski, Valentin N., Hu, Rongwei, Petrovic, Cedomir, David, Bohumil, Barudžija, Tanja, "Perturbed Angular Correlation Investigation of the Electric Field Gradient At Ta-181 Probe in the Hf2ni7 Compound" in Nuclear technology and radiation protection, 27, no. 2 (2012):95-102,
https://doi.org/10.2298/NTRP1202095C . .

TY  - CONF
AU  - Cekić, Božidar Đ.
AU  - Umićević, Ana
AU  - Ivanovski, Valentin N.
AU  - Belošević-Čavor, Jelena
AU  - Koteski, Vasil J.
AU  - Hu, Rongwei
AU  - Petrović, Čedomir
PY  - 2010
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6992
AB  - The perturbed angular correlation method has been employed to study the temperature dependence of the Ta-181 hyperfine interaction parameters in the poly-crystalline intermetallic compound alpha HfNi. At ambient temperature the frequency of the electric quadrupole interaction was omega(Q) = 26.0(2) Mrad/s and the asymmetry parameter eta = 0.22(1). The magnitude of the observed electric field gradient decreases with increasing temperature from 78 to 900 K. The calculations were done using the augmented plane wave plus local orbitals method as implemented in the WIEN2k code, using the generalized gradient approximation. In addition, a supercell calculation with Ta impurity located at the hafnium site was performed. The obtained result is in a good agreement with the experiment.
C3  - Hyperfine Interactions
T1  - Thermal evolution of the electric field gradient at Ta-181 in alpha HfNi
VL  - 196
IS  - 1-3
SP  - 339
EP  - 347
DO  - 10.1007/s10751-009-0135-1
ER  - 

@conference{
author = "Cekić, Božidar Đ. and Umićević, Ana and Ivanovski, Valentin N. and Belošević-Čavor, Jelena and Koteski, Vasil J. and Hu, Rongwei and Petrović, Čedomir",
year = "2010",
abstract = "The perturbed angular correlation method has been employed to study the temperature dependence of the Ta-181 hyperfine interaction parameters in the poly-crystalline intermetallic compound alpha HfNi. At ambient temperature the frequency of the electric quadrupole interaction was omega(Q) = 26.0(2) Mrad/s and the asymmetry parameter eta = 0.22(1). The magnitude of the observed electric field gradient decreases with increasing temperature from 78 to 900 K. The calculations were done using the augmented plane wave plus local orbitals method as implemented in the WIEN2k code, using the generalized gradient approximation. In addition, a supercell calculation with Ta impurity located at the hafnium site was performed. The obtained result is in a good agreement with the experiment.",
journal = "Hyperfine Interactions",
title = "Thermal evolution of the electric field gradient at Ta-181 in alpha HfNi",
volume = "196",
number = "1-3",
pages = "339-347",
doi = "10.1007/s10751-009-0135-1"
}

Cekić, B. Đ., Umićević, A., Ivanovski, V. N., Belošević-Čavor, J., Koteski, V. J., Hu, R.,& Petrović, Č.. (2010). Thermal evolution of the electric field gradient at Ta-181 in alpha HfNi. in Hyperfine Interactions, 196(1-3), 339-347.
https://doi.org/10.1007/s10751-009-0135-1

Cekić BĐ, Umićević A, Ivanovski VN, Belošević-Čavor J, Koteski VJ, Hu R, Petrović Č. Thermal evolution of the electric field gradient at Ta-181 in alpha HfNi. in Hyperfine Interactions. 2010;196(1-3):339-347.
doi:10.1007/s10751-009-0135-1 .

Cekić, Božidar Đ., Umićević, Ana, Ivanovski, Valentin N., Belošević-Čavor, Jelena, Koteski, Vasil J., Hu, Rongwei, Petrović, Čedomir, "Thermal evolution of the electric field gradient at Ta-181 in alpha HfNi" in Hyperfine Interactions, 196, no. 1-3 (2010):339-347,
https://doi.org/10.1007/s10751-009-0135-1 . .