Coexistence of high magnetic and dielectric properties in Ni-Zr co-doped barium hexaferrites

Enhancement in the dielectric and magnetic properties of Ni2+–Cu2+ co-doped BaFe11Cu1−xNixO19 hexaferrites (0.0 ≤ x ≤ 1.0)

“…Moreover, the permittivity may also be affected by the transition of some of the Ni 2+ ions to Ni 3+ with an increase in the Ni 2+ doping content. 16 Here, the 3 0 value was found to be highest for the BaFe 11 Ni 1 O 19 (x = 1.0) sample, which is ascribed to its highest dipole density (i.e., Fe 2+ /Fe 3+ and Ni 2+ /Ni 3+ ) among the prepared samples. This results in a colossal permittivity (∼10 5 ) for the BaFe 11 Ni 1 O 19 sample, which is two orders of magnitude higher than the permittivity of the pure BaFe 12 O 19 sample and also among the highest reported values to date.…”

“…Further, it is anticipated that the magnetic nature of this ion pair will maintain the magnetic interactions, which may enhance the magnetization and reduce the coercivity depending on their preferential occupation of the octahedral sites in Mtype hexaferrites. 13,16 Therefore, different compositions of BaFe 11 Cu 1−x Ni x O 19 hexaferrites with x = 0.0, 0.25, 0.50, 0.75, and 1.0 were prepared using the co-precipitation method, and then investigated for their microstructural, magnetic, and dielectric characteristics. Based on the obtained results, we found the coexistence of considerable high saturation magnetization (50-73 emu g −1 ) and dielectric permittivity (∼10 3 -10 5 @10 Hz) in the prepared samples.…”

Low-frequency electrical response related to oxygen vacancies in Al3+ substituted M-type hexaferrite

“…The localization length is calculated from equation (11). The value of ε r is measured by using the LCR meter at 1 kHz and is in the range of ∼10 2 [70,71]. The localization lengths of all the samples are shown in table 1 and are found to be in the range of ∼10 −11 m. The values of the localization length (ξ ES ) are smaller than the inter-ionic distance for the hexaferrite, which is about 1-3 Å, (R hop ⩾ ξ ES ).…”

Influence of Gd and Ni doping on the structural, morphological, and magnetic properties of M-type calcium hexaferrite

“…Four of these sites are tetrahedral (4f1), octahedral (2a, 12k), and trigonal bipyramidal (2b) in these sites. 27 Fe 3+ ions have an up (↑) spin orientation at sites 2a, 2b, and 12k, and a down (↓) spin orientation at sites 4f1 and 4f2. One formula unit contains twelve Fe 3+ ions, distributed as follows: one on site 2a, one on site 2b, six on site 12k, two on site 4f1, and two on site 4f2.…”