The Iron Holmium Binary System And Related Magnetic Properties

Nuclear Science Abstracts

The Iron-holmium Binary System and Related Magnetic Properties

"The iron-holmium phase diagram was investigated to determine the alloying behavior of these two metals and to determine the magnetic properties of some of the iron-holmium alloys which formed intermediate phases. The iron-holmium binary system was determined by three experimental techniques, differential thermal analysis (DTA), x-ray diffraction, and metallography. A phase diagram with three eutectic points and four intermediate phases was constructed from the experimental data. The two phases, Ho6Fe23 and Ho2Fe1--, melted congruently at 1322°C and 1343°C respectively. HoFe2 and HoFe3 melted incongruently at 1288°C and 1293°C respectively. Neutron diffraction investigations were made on the intermediate phases Ho6Fe23 and HoFe2 to obtain information on their magnetic structures. From the plots of magnetic ordering vs. temperature, the Curie temperature of Ho6Fe23 was placed at 500°K, and that of HoFe2 at 600°K. Intensity calculations for the Ho6Fe23 data showed a ferrimagnetic structure with saturation moments of 2.25 and 9.3 [mu][subscript B] for iron and holmium respectively. The magnetic and chemical cells of Ho6Fe23 were coincidental, while the magnetic cell of HoFe2 was approximately four times larger than its chemical cell"--Abstract, leaf i.

Bibliography of Magnetic Materials and Tabulation of Magnetic Transition Temperatures

This referenced compilation of magnetic transition temperatures represents (with the Addendum) papers actually received by the RMIC through May 1972 and consists of two lists (alphabetical by compounds), one for Curie and one for Neel temperatures. Where different values appeared in the literature for a single compound, all are listed with sepa rate references given for each. There is no attempt at critical evaluation, which, except for a few welt-studied and well characterized materials, would hardly be worth the effort. All that one can say for most of the compounds is that for a given material with a certain (or all too often uncertain) history of preparati'on and treatment, stoichiometry, homoge neity, and chemical or structural purity a magnetic transition was indicated at the temperature(s) listed. Only when the reasons for different values are explicitly stated in the literature do they appear as brief comments in the body of the lists. In order to include the most recent data, and to eliminate the delay involved in recomposition of the lists, an addendum is provided. While this requires the perusal of two lists rather than one, it does ensure that the compilation represents the entire RMIC collection at the moment of going to press. The 2478 references are restricted to those papers specifying a Curie or Neel temperature and do not reflect the complete magnetics literature even for the materials listed.