Title :
Magnetic properties of goethite in radulae of limpets
Author :
Huang, C.M. ; Li, C.-W. ; Deng, M.C. ; Chin, T.S.
Author_Institution :
Tsing Hua Univ., Hsinchu, Taiwan
fDate :
9/1/1992 12:00:00 AM
Abstract :
Radular formation in the limpet, Acmae striata, was explored by magnetic measurements, Mossbauer spectroscopy, X-ray diffraction, and electron microscopy. It was found that, in premature radula, acicular goethite alone precipitated in the matrix-mediated manner. It grows extensively to be interlocking masses in a cusp region of detected in the porous region. A new mineral phase, hisingerite, was identified to coexist with goethite and an amorphous silicate. The goethite has a relative susceptibility of 2.5×10-5. An oxidation-reduction turned the goethite to gamma-Fe2O3 with a coercivity of 250 Oe and a saturation magnetization of only 6.65 emu/g due to the dilution effect of coexisting silicates
Keywords :
Mossbauer effect; X-ray diffraction examination of materials; antiferromagnetic properties of substances; biomagnetism; coercive force; iron compounds; magnetic susceptibility; minerals; Acmae striata; Fe2Si2O5(OH)5.2H 2O phase; Fe2Si2O5(OH)5H2 O; Mossbauer spectroscopy; X-ray diffraction; amorphous silicate; antiferromagnetic structure; coercivity; gamma Fe2O3; goethite; hisingerite; magnetic properties; magnetic recording materials; mineral phase; oxidation-reduction; radulae of limpets; relative susceptibility; saturation magnetization; Amorphous materials; Coercive force; Electron microscopy; Magnetic force microscopy; Magnetic properties; Magnetic variables measurement; Minerals; Saturation magnetization; Spectroscopy; X-ray diffraction;
Journal_Title :
Magnetics, IEEE Transactions on
