Interplay between structure and magnetism and effect of size of SmMn2O5 nanorods
碩士 === 中原大學 === 物理研究所 === 101 === Five sizes SmMn2O5 nanorods are fabricated by performing different annealing temperatures of 300、500、700、900、1100 °C. X-ray diffraction scheme is used to determinate the crystal structure and purity. All samples are form in orthorhombic Pbam phase. High-resolution T...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2013
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| Online Access: | http://ndltd.ncl.edu.tw/handle/72420959028237351793 |
| Summary: | 碩士 === 中原大學 === 物理研究所 === 101 === Five sizes SmMn2O5 nanorods are fabricated by performing different annealing temperatures of 300、500、700、900、1100 °C. X-ray diffraction scheme is used to determinate the crystal structure and purity. All samples are form in orthorhombic Pbam phase. High-resolution TEM image and SAED pattern revealed the long and short axis of 300、500、700、900、1100 °C samples can be wrote in the form of long axis × short axis as 25(17) nm×58(42) nm、23(13) nm×75(36) nm、31(13) nm×88(34) nm、32(21) nm×92(73) nm、52(25) nm×126(53) nm. Furthermore, the long axis of all samples is growth along c axis, which can be used to label the sample name by the symbol <LC>.
Magnetic susceptibility experiments display an antiferromagnetic (AFM) peak is found in <LC>=58、88、92、126 nm samples at 25、29、29.5、30 K, respectively. This observation revealed the effect of size is majorly weaken the AFM ordering and shifted the peak to the lower temperature. The M-H curve shows a small hysteresis loopfor all samples. The coercivity are also increased with increasing <LC>.
Varied temperature Raman and x-ray diffraction are performed in <LC>=92、126 nm samples. A Raman peak shifted at 150 K in <LC>=92 nm sample. Similar peak shift are also found at 150 K and 250 K in <LC>=126 nm one. These observation echoes the observation of Mn-O at the same temperature ranges.
The effect of size of SmMn2O5 weak the AFM peak at low temperature. The structure distortion shifted the Raman peak and further results spin-orbit interaction above magnetic ordering temperature.
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