Nd-Zn Co-substituted M-Type Strontium Hexaferrites with Enhanced Magnetic Properties

Abstract

In this work, we report the synthesis of Nd-Zn co-substituted M-type strontium hexaferrites Sr1-xNdxFe12-xZnxO19 (0.0 ≤ x ≤ 0.5) by the solid-state method. The analysis of X-ray diffraction (XRD) shows that the single M-type hexaferrite structure can be obtained as the doping concentration is lower than 0.3, while the other side phase (α-Fe2O3) will appear in the XRD patterns for x ≥ 0.3. Furthermore, the specific hexagonal structure is also confirmed by Fourier transform infrared (FTIR) spectroscopy, and field emission scanning electron microscopy (FE-SEM) also discloses the micromorphology of the series samples over the entire range of substitution. Through the systematical magnetic measurements, enhanced magnetic properties can be acquired due to the effective substitution, especially for intrinsic coercivity (Hcj), which increases from 1800 Oe (x = 0.0) to 3230 Oe (x = 0.5) at room temperature. In addition, the doping sample also exhibits a considerable thermal stability because of a high ferromagnetic–paramagnetic (FM–PM) transition temperature (i.e., Curie temperature TC). In consideration of the magnetic performance and high FM–PM phase temperature, Sr1-xNdxFe12-xZnxO19 series of samples can be considered as promising candidates for magnetic recording devices because of such high saturation magnetization and considerable coercivity.