<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><p>Two nanocrystalline samples of TiC+SiC+20%C (sample 1) and Si3N4+Si(C,N)+Ti(C,N)+1%C (sample 2) were prepared by non-hydrolytic sol-gel method. The latter sample was produced from sample 1, by subjecting it to additional annealing at high temperature. XRD measurements showed the presence of aggregates of cubic SiC+TiC nanoparticles (10 to 30 nm in size). In both samples, a very narrow electron paramagnetic resonance (EPR) line originating from localized magnetic centers was centered at g
                        eff∼2. At T = 130 K, we registered the linewidths ΔH
                        pp = 1.41(2) G and ΔH
                        pp = 2.92(2) G for the sample without and with thermal annealing, respectively. For the non-annealed sample, the resonance line was fitted by a Lorentzian line in the low temperature range, and by a Dysonian line above 70 K, which indicates a significant change in electrical conductivity. Therefore, thermal annealing can significantly improve the transport properties of samples. An analysis of the temperature dependence of the EPR parameters (g-factor, linewidth, integrated intensity) showed that thermal annealing has a significant impact on the reorientation processes of localized magnetic centers.</p></abstract>

Two nanocrystalline samples of TiC+SiC+20%C (sample 1) and Si3N4+Si(C,N)+Ti(C,N)+1%C (sample 2) were prepared by non-hydrolytic sol-gel method. The latter sample was produced from sample 1, by subjecting it to additional annealing at high temperature. XRD measurements showed the presence of aggregates of cubic SiC+TiC nanoparticles (10 to 30 nm in size). In both samples, a very narrow electron paramagnetic resonance (EPR) line originating from localized magnetic centers was centered at g
                        eff∼2. At T = 130 K, we registered the linewidths ΔH
                        pp = 1.41(2) G and ΔH
                        pp = 2.92(2) G for the sample without and with thermal annealing, respectively. For the non-annealed sample, the resonance line was fitted by a Lorentzian line in the low temperature range, and by a Dysonian line above 70 K, which indicates a significant change in electrical conductivity. Therefore, thermal annealing can significantly improve the transport properties of samples. An analysis of the temperature dependence of the EPR parameters (g-factor, linewidth, integrated intensity) showed that thermal annealing has a significant impact on the reorientation processes of localized magnetic centers.

Effect of annealing on EPR spectra of Ti-Si-C-N samples

Department of Solid State Physics, School of Physics, Faculty of Sciences, University of Athens, Panepistimiopolis, 15 784, Zografos, Athens, Greece

Institute of Physics, West Pomeranian University of Technology, Al. Piastow 48, 70-311, Szczecin, Poland

Hellenic Air Force Academy, Dekeleia, Greece

Institute of Materials Science and Engineering, West Pomeranian University of Technology, Al. Piastow 19, 70-310, Szczecin, Poland

Materials Science-Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Effect of annealing on EPR spectra of Ti-Si-C-N samples"}

Two nanocrystalline samples of TiC+SiC+20%C (sample 1) and Si3N4+Si(C,N)+Ti(C,N)+1%C (sample 2) were prepared by non-hydrolytic sol-gel method. The latter...

Effect of annealing on EPR spectra of Ti-Si-C-N samples

Online veröffentlicht: 16. Juni 2012

Seitenbereich: 23 - 31

DOI: https://doi.org/10.2478/s13536-012-0004-5

Schlüsselwörter
TiC, EPR, magnetic properties

© 2012 Wroclaw University of Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Effect of annealing on EPR spectra of Ti-Si-C-N samples

Online veröffentlicht: 16. Juni 2012

Seitenbereich: 23 - 31

DOI: https://doi.org/10.2478/s13536-012-0004-5

SchlüsselwörterTiC, EPR, magnetic properties

© 2012 Wroclaw University of Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Schlüsselwörter
TiC, EPR, magnetic properties