http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Crystallographic and Magnetic Properties of the Hyperthermia Material CoFe2O4@AlFe2O4
최현경,안미정,엄원영,임세월,심인보,김철성,김삼진 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.70 No.2
Hard/soft CoFe2O4@AlFe2O4 core/shell nanoparticles were prepared by using a high temperature thermal decomposition method with seed-mediated growth. The structural, magnetic and thermal properties of the nanoparticles were investigated by using X-ray diffraction, vibrating sample magnetometer, MagneTherm, and M¨ossbauer spectroscopy. The crystal structure of nanoparticles was determined to be cubic spinel ferrite with space group Fd-3m. The CoFe2O4 nanoparticles were found to show high magnetization and coercivity while AlFe2O4 nanoparticles were found to show low magnetization and coercivity. The CoFe2O4@AlFe2O4 core/shell nanoparticles showed intermediate values of magnetization and the coercivity between those of CoFe2O4 and AlFe2O4. Also, the blocking temperature (TB) of the nanoparticles (NPs) was observed to be 280, 50, and 225 K for CoFe2O4, AlFe2O4 and CoFe2O4@AlFe2O4, respectively. The core/shell ferrite shows a TB near 225 K, associated with the harder CoFe2O4 NPs. Temperatures below 225 K, the zero-fieldcooled curves show changes in their slopes at a temperature near 50 K, corresponding to the second blocking temperature associated with the softer AlFe2O4 NPs.