Structural, Dielectric, and Magneto‐Optical Properties of Al‐Cr Substituted M‐Type Barium Hexaferrite

• Published in: Physica status solidi. A, Applications and materials science Applications and materials science, 2019-08, Vol.216 (16), p.n/a
• Main Authors: Carol Trudel, Tchouank Tekou, Mohammed, Jibrin, Hafeez, Hafeez Yusuf, Bhat, Bilal Hamid, Godara, Sachin Kumar, Srivastava, Ajeet Kumar
• Format: Article
• Language: English
• Subjects: Barium; Barium hexaferrite; Chromium; Coercivity; dielectric constant; dielectric loss; Dielectric properties; Grain boundaries; Magnetic properties; Magnetic recording; Magnetic storage; Magnetic tape; Materials substitution; Optical properties; Permittivity; Photomicrographs; Plates (structural members); Recording instruments; remanent magnetization; saturation magnetization; Sol-gel processes
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201800928

M‐type barium hexaferrite, BaFe12‐2xAlxCrxO19 (x = 0.0, 0.2, 0.4), is prepared using sol–gel auto‐combustion method and calcined at 1000 °C for 7 h. The effects of Al‐Cr substitution on the properties of the barium hexaferrite are investigated through XRD, FTIR, FESEM, UV‐vis‐NIR, VSM, and impedance analyzer. XRD analysis reveals the formation of hexaferrites with single phase and no impurity phase is detected. FTIR spectra show bands at 437 and 590 cm−1 which indicate the possible of hexaferrites. The micrographs of FESEM shows agglomerated grains with hexagonal plate‐like shape while the EDX spectra confirm the composition of the synthesized samples. Dielectric constant decreases abruptly at lower frequencies and an increment in dielectric constant at much higher frequency region is observed. Grain boundaries dominate the AC conductivity at lower frequencies while the grains could be responsible for the observed dispersion at higher frequencies. The values of coercivity for all the samples are found to be greater than 1200 Oe; this makes the prepared samples useful for high‐density perpendicular magnetic recording media. Sol–gel auto‐combustion method is used to synthesize BaFe12‐2xAlxCrxO19 (x = 0.0, 0.2, 0.4) nanoparticles. High frequency improvement of dielectric constant makes the synthesized samples vital for electronic device application and the magnetic parameters are within the range of application in high‐density perpendicular magnetic recording application.