Low temperature far-infrared complete reflectivity spectra of single crystal Ba hexaferrite

Raman Spectra and Vibrational Analysis of BaFe12O19Hexagonal Ferrite

“…However, when the temperature is decreased, no extra bands are observed, which would explain the appearance of a superstructure due to ordering of the Fe ions. Thus, the number of bands and their reduction when the temperature is decreased favors model a or model b with a potential barrier lower than 80 K. The foregoing discussion is strengthened by the BaM IR spectra at 80 and 300 K of Nicolic et al (5).…”

“…Therefore, it is useful to discuss the BaM IR spectra reported in the literature. The IR spectra of BaM reported by Nicolic et al (4,5) exhibit three bands at low frequency: two bands of A S symmetry at 59 and 124 cm\ and one band of E S symmetry at 95 cm\. Belotto et al (7) found for BaM two low-frequency bands at 102 and 124 cm\ and assigned both to vibrations of the Ba> cation.…”

“…Another interesting point concerning the IR data of Nicolic et al (4,5) is the observed splitting of TO-and LOfrequency for a given mode. In general, the magnitude of the splitting gives an approximated order of the degree of ionicities.…”

“…There is still controversy about the symmetry of the vibrational modes in the literature (4)(5)(6)(7)(8).…”

“…Polarized far-infrared reflection spectra have been used to investigate the optical and dielectric properties (4,5). Eremenko et al (6) studied infrared (IR) reflection spectra of cooled BaM single crystals.…”