M¨ossbauer Studies of Ferrihydrite for Fischer-Tropsch Catalysts
M¨ossbauer Studies of Ferrihydrite for Fischer-Tropsch Catalysts
Jung Tae Lim(Kookmin University); 김철성(국민대학교); Dong Hyun Chun(Korea Institute of Energy Research); 박지찬(Korea Institute of Energy Research)
68권 2호, 302~305쪽
초록
The 6-line ferrihydrite sample for Ficher-Tropsch catalysts was prepared by using a combination of a co-precipitation technique and a spraydrying method. The crystallographic and magnetic properties of 6-line ferrihydrite sample were investigated by using x-ray diffractometer (XRD), vibrating sample magnetometer (VSM), and M¨ossbauer spectrometer. The XRD patterns of the ferrihydrite sample, measured at 295 K, showed 6-lines peak and its structure was found to be a single-phased hexagonal with space group of P3m1 according to JCPDS card. The temperaturedependent magnetization curves were measured under 1000 Oe between 4.2 and 300 K, and showed blocking temperature (TB) around 110 K. Also, M¨ossbauer spectra of the 6-line ferrihydrite sample were taken at various temperatures ranging from 4.2 to 295 K. At temperature below TB, the obtained spectra were analyzed as two-sextets for Fe sites, while At temperature above TB, the obtained spectra showed a doublet due to relaxation, resulting from the spin dynamic effect.
Abstract
The 6-line ferrihydrite sample for Ficher-Tropsch catalysts was prepared by using a combination of a co-precipitation technique and a spraydrying method. The crystallographic and magnetic properties of 6-line ferrihydrite sample were investigated by using x-ray diffractometer (XRD), vibrating sample magnetometer (VSM), and M¨ossbauer spectrometer. The XRD patterns of the ferrihydrite sample, measured at 295 K, showed 6-lines peak and its structure was found to be a single-phased hexagonal with space group of P3m1 according to JCPDS card. The temperaturedependent magnetization curves were measured under 1000 Oe between 4.2 and 300 K, and showed blocking temperature (TB) around 110 K. Also, M¨ossbauer spectra of the 6-line ferrihydrite sample were taken at various temperatures ranging from 4.2 to 295 K. At temperature below TB, the obtained spectra were analyzed as two-sextets for Fe sites, while At temperature above TB, the obtained spectra showed a doublet due to relaxation, resulting from the spin dynamic effect.
- 발행기관:
- 한국물리학회
- 분류:
- 물리학