MAGNETIC PROPERTIES OF HEMATITE SINGLE CRYSTALS. I. MAGNETIZATION ISOTHERMS, ANTIFERROMAGNETIC SUSCEPTIBILITY, AND WEAK FERROMAGNETISM OF NATURAL CRYSTAL

Journal Article · Tue Dec 15 00:00:00 EST 1959 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.116.1447· OSTI ID:4187095

Lin, S T

Two sets of magnetization isotherms of pure natural hematite single crystals from Elba were obtained in the temperature range from 488 deg K down to liquid helium temperatures. The first set of curves, along a certain direction in the basal plane, support Neel's magnetic model of a superposition of a weak ferromagnetism on a normal antiferromagnetism. The second set of curves, along the ternary axis, display very unusual form. The analysis of the isotherms shows that the antiferromagnetic susceptibility-temperature curves, x - T, are in good agreement with those obtained by Neel and Pauthenet but the weak ferromagnetic properties are apparently contradictory to their interpretations. The spontaneous magnetization-temperature curves, sigma /sub 0/-T, indicate that there is no isotropic ferromagnetism, and that the weak anisotropic ferromagnetism in the basal plane above transition and along the ternary axis below transition seems to have the same nature and origin. The X - T and sigma / sub 0/ - T curves show that the wide transition takes place gradually and continuously. A general magnetic model of canted antiferromagnetism with unequal sublattice moments was proposed which explains all the experimental data satisfactorily. From the present model Haigh's data of remanent magnetization of hematite powder seems to be explained naturally. (auth)

• Research Organization: Massachusetts Inst. of Tech., Cambridge
• NSA Number: NSA-14-009806
• OSTI ID: 4187095
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Vol. Vol: 116; Other Information: Orig. Receipt Date: 31-DEC-60
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

METALS, CERAMICS, AND MATERIALS
ANISOTROPY
ANTIFERROMAGNETISM
CRYSTALS
DIAGRAMS
FERROMAGNETIC MATERIALS
HELIUM
HEMATITE
IMPURITIES
IRON OXIDES
LATTICES
LIQUIDS
LOW TEMPERATURE
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MAGNETISM
MONOCRYSTALS
POWDERS
SUSCEPTIBILITY
TEMPERATURE
TESTING