Investigation of the effects of Tm3+ on the structural, microstructural, optical, and magnetic properties of Sr hexaferrites

SrTmxFe(12-x)O(4) (0.00 <= x <= 0.10) hexaferrites (HFs) are produced successfully using a sol-gel approach. The structural, optical, and magnetic properties are investigated. The hexagonal phase is confirmed for all the products. The magnetization is measured with respect to the applied magnetic field, M(H). The magnetic parameters including saturation magnetization M-s, remanence M-r, squareness ratio (SQR = M-r/M-s), coercivity H-c, and magnetic moment n(B) are deduced at room (300 K; RT) and low (10 K) temperatures. It is shown that the ferrimagnetic nature and Tm3+ substitutions lead to decreases in the magnetization and coercivity magnitudes. The results on magnetic properties are investigated extensively with respect to the structural and microstructural properties. The SQR values indicate the formation of a single magnetic domain for the x = 0.0 sample and a multi-magnetic domain structure for the Tm3+-substituted Sr HFs (x >= 0.02). The obtained Hc values suggest that the produced HFs are promising candidates for potential magnetic recording applications.