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Grain size-dependent magnetic and electric properties in nanosized YMnO3 multiferroic ceramics.

Han TC, Hsu WL, Lee WD - Nanoscale Res Lett (2011)

Bottom Line: The magnetic characterization indicates that with increasing grain size, the antiferromagnetic (AFM) transition temperature increases from 52 to 74 K.Further analysis suggests that the rising of AFM transition temperature with increasing grain size should be from the structural origin, in which the strength of AFM interaction as well as the electrical polarization is dependent on the in-plane lattice parameters.Furthermore, among all samples, the sample with grain size of 95 nm is found to have the smallest leakage current density (< 1 μA/cm2).PACS: 75.50.Tt, 75.50.Ee, 75.85.+t, 77.84.-s.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Applied Physics, National University of Kaohsiung, Kaohsiung 811, Taiwan. tchan@nuk.edu.tw.

ABSTRACT
Magnetic and electric properties are investigated for the nanosized YMnO3 samples with different grain sizes (25 nm to 200 nm) synthesized by a modified Pechini method. It shows that magnetic and electric properties are strongly dependent on the grain size. The magnetic characterization indicates that with increasing grain size, the antiferromagnetic (AFM) transition temperature increases from 52 to 74 K. A corresponding shift of the dielectric anomaly is observed, indicating a strong correlation between the electric polarization and the magnetic ordering. Further analysis suggests that the rising of AFM transition temperature with increasing grain size should be from the structural origin, in which the strength of AFM interaction as well as the electrical polarization is dependent on the in-plane lattice parameters. Furthermore, among all samples, the sample with grain size of 95 nm is found to have the smallest leakage current density (< 1 μA/cm2).PACS: 75.50.Tt, 75.50.Ee, 75.85.+t, 77.84.-s.

No MeSH data available.


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Leakage current as function of applied electric field for the YMnO3 samples. Samples have different grain sizes (25 nm to 200 nm).
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Figure 7: Leakage current as function of applied electric field for the YMnO3 samples. Samples have different grain sizes (25 nm to 200 nm).

Mentions: To further probe the electrical leakage effect, the leakage current were measured for all the samples at room temperature as shown in Figure 7. The leakage current density is large (> 100 μA/cm2) for the sample with grain size of 25 nm. On the other hand, the leakage currents are much decreased by about four orders of magnitude for the samples with grain size larger than 45 nm. In addition, it is not expected that the sample with larger grain size of 200 nm is not the less leaky sample. As for the improvement of the leakage properties, it should be associated with the high denseness of the ceramics [22].


Grain size-dependent magnetic and electric properties in nanosized YMnO3 multiferroic ceramics.

Han TC, Hsu WL, Lee WD - Nanoscale Res Lett (2011)

Leakage current as function of applied electric field for the YMnO3 samples. Samples have different grain sizes (25 nm to 200 nm).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211257&req=5

Figure 7: Leakage current as function of applied electric field for the YMnO3 samples. Samples have different grain sizes (25 nm to 200 nm).
Mentions: To further probe the electrical leakage effect, the leakage current were measured for all the samples at room temperature as shown in Figure 7. The leakage current density is large (> 100 μA/cm2) for the sample with grain size of 25 nm. On the other hand, the leakage currents are much decreased by about four orders of magnitude for the samples with grain size larger than 45 nm. In addition, it is not expected that the sample with larger grain size of 200 nm is not the less leaky sample. As for the improvement of the leakage properties, it should be associated with the high denseness of the ceramics [22].

Bottom Line: The magnetic characterization indicates that with increasing grain size, the antiferromagnetic (AFM) transition temperature increases from 52 to 74 K.Further analysis suggests that the rising of AFM transition temperature with increasing grain size should be from the structural origin, in which the strength of AFM interaction as well as the electrical polarization is dependent on the in-plane lattice parameters.Furthermore, among all samples, the sample with grain size of 95 nm is found to have the smallest leakage current density (< 1 μA/cm2).PACS: 75.50.Tt, 75.50.Ee, 75.85.+t, 77.84.-s.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Applied Physics, National University of Kaohsiung, Kaohsiung 811, Taiwan. tchan@nuk.edu.tw.

ABSTRACT
Magnetic and electric properties are investigated for the nanosized YMnO3 samples with different grain sizes (25 nm to 200 nm) synthesized by a modified Pechini method. It shows that magnetic and electric properties are strongly dependent on the grain size. The magnetic characterization indicates that with increasing grain size, the antiferromagnetic (AFM) transition temperature increases from 52 to 74 K. A corresponding shift of the dielectric anomaly is observed, indicating a strong correlation between the electric polarization and the magnetic ordering. Further analysis suggests that the rising of AFM transition temperature with increasing grain size should be from the structural origin, in which the strength of AFM interaction as well as the electrical polarization is dependent on the in-plane lattice parameters. Furthermore, among all samples, the sample with grain size of 95 nm is found to have the smallest leakage current density (< 1 μA/cm2).PACS: 75.50.Tt, 75.50.Ee, 75.85.+t, 77.84.-s.

No MeSH data available.


Related in: MedlinePlus