Size effect on dielectric properties of rare earth multiferroics nanorods
碩士 === 中原大學 === 物理研究所 === 105 === GdMn2O5 nanorods were prepared by hydrothermal method, and different sizes of nanorods were sintered by thermal annealing. The samples were characterized by X-ray powder diffractometer, field emission electron microscopy (FE-TEM), electrical measuring instrument and...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2017
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| Online Access: | http://ndltd.ncl.edu.tw/handle/3dt9p2 |
| Summary: | 碩士 === 中原大學 === 物理研究所 === 105 === GdMn2O5 nanorods were prepared by hydrothermal method, and different sizes of nanorods were sintered by thermal annealing. The samples were characterized by X-ray powder diffractometer, field emission electron microscopy (FE-TEM), electrical measuring instrument and physical property measuring instrument (PPMS).
A magnetic susceptibility peak was found at 40 K as sample <Lc> larger than 80nm. Varied temperature XRD experiments show an anomaly peak at 27.3º in <Lc>=80 nm but not in 67 nm sample as temperature cooling down to 27 K. This is not expected in orthorhombic Pbnm structure. We believe this is correlated with the magnetic and structural critical size in between <Lc> = 80 nm and <Lc> = 67 nm. The peak value of ferroelectric phase transition for all samples are at 43 K, and the peak value of ferroelectric phase of 210 nm is 35 K, while the peak of 80 nm and 67 nm is 27 K. This shows that the ordering of ferroelectrics begins to change between <Lc> = 210 nm and 80 nm.
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