INVESTIGATION OF ORDERED MAGNETIC STATES AND THEIR CORRELATIONS TO OPTICAL AND ELECTRICAL PROPERTIES OF SELECTED MATERIALS.
Abstract
A report is given of electron spin resonance (ESR) studies of Cr(3+) in Al2O3 and Li2Ge7O15. Lineshape and linewidth measurements of ruby samples were carried out at K-band both inside and outside the microwave cavity. Mosaic, strain, and hyperfine splitting were found to contribute significantly to the lineshape. A new lineshape expression for the mosaic contribution was proposed. A method of testing the quality of large pieces of ruby, e.g., laser rods, without the need for cutting or any other destructive process was conceived under this contract. The magnetic properties of Y3Fe3.2Ga1.8O12 are reported based upon ferromagnetic resonance linewidth, anisotropy constants, and magnetization measurements. Particular attention is paid to the effect of 'impurities' such as unordered Fe(3+) resulting from gallium substitution. Critical exponents were determined from magnetization measurements near the Curie point and are compared to Anderson's results for pure YIG. Anomalies in the susceptibility tensor Xyx of the spin-flop transition in CuCl2.2H2O were studied. The effect of the sample shape is included exactly through the use of a 2 x 2 demagnetizing tensor. Asymmetries in Xyx could only be accounted for by postulating the existence of domains and/or inclusions in the sample. The polarized absorption spectrum of Cr(3+) in Li2Ge7O15 and the fluorescence lifetime in heavily doped ruby is reported. The general characteristics of the polarized spectrum of Cr(3+) in Li2Ge7O15 is presented in an energy level diagram. Uneven splittings of the R1 and R2 lines of ruby suggest the possibility of two inequivalent sites for the Cr(3+) ion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1967
- Accession Number
- AD0666676
Entities
People
- A. Novanski
- B. Di Bartolo
- J. H. Terrell
- J. Schwartz
- K. Gooen