Accession Number : AD0440250


Title :   IMPROVEMENT OF THE FERROMAGNETIC RESONANCE LINEWIDTH OF SINGLE-CRYSTAL ZNY (BA2ZN2FE12O22) BY A NEW GROWTH TECHNIQUE,


Corporate Author : COLLEGE OF WILLIAM AND MARY WILLIAMSBURG VA


Personal Author(s) : Tauber,A ; Dixon,Samuel ,Jr ; Savage,R O


Report Date : Jan 1964


Pagination or Media Count : 2


Abstract : By using a new growth technique, ferromagnetic resonance linewidths as low as 8.0 Oe can be obtained in ZnY single crystals at room temperature and 9.0 Mc/sec. These crystals were grown in platinum crucibles from BaO-B203 melts. The melts were found to be less volatile and less viscous than NaFeO2 melts. Annealing reduced the linewidth. The best conditions consisted of annealing raw crystals at 750 C in 1 atm of oxygen for 24 h. This treatment reduced the ferrous ion concentration to below the limit of detection, 0.01%, and is considered the major factor in linewidth reduction. These samples were then ground into spheres and polished with successively finer grit abrasives. An exponential decrease in the linewidth was observed as a function of grit size. Linewidth measurements were made using the standard cavity perturbation technique. The diameters of the samples ranged from 0.018 to 0.030 in. The orientation of spheres in the cavity was such that the microwave magnetic field and the applied field were perpendicular to each other in the plane of easy magnetization of the material. (Author)


Descriptors :   *FERROMAGNETIC MATERIALS , RESONANCE , SINGLE CRYSTALS , CRYSTAL GROWTH , BARIUM COMPOUNDS , ZINC COMPOUNDS , MAGNETIC FIELDS , FERRITES , IMPURITIES , ELECTRICAL RESISTANCE , LINE SPECTRA , MEASUREMENT


Distribution Statement : APPROVED FOR PUBLIC RELEASE