Structural phase transition and magnetic anisotropy of La-substitutedM-type Sr hexaferrite

Microwave absorption properties of La-substituted M-type strontium ferrites

“…The results are given in Table 1. It can be seen that the lattice constant "a" increases and "c" decreases with the substitution amount x increasing, which is consistent with previous work [31,42]. Comparing with undoped pure ferrite, with the increase of lanthanum substitution amount, the grain sizes of the ferrites get smaller.…”

“…Fig. 2 shows the Ms for the La-substituted strontium hexaferrites; and the hyperfine field and isomer shift of the five Fe ions sublattices derived from Ms are shown in Table 2 [32,42]. In the lattice, the nearest ferric ion neighbor for Sr 2+ is the 2b site Fe 3+ , when the La 3+ substituting Sr 2+ , the environment of the 2b site will be influenced and that will affect the hyperfine fields and isomer shift on 2b site.…”

Magnetic anisotropy and magnetostriction of

“…These new ferrites may be understood better by considering the unusual behavior of LaFe 12 O 19 . Therefore the physical properties of this interesting compound were studied intensively as recently published [6]. The purpose of this work is to extend these investigations in order to understand the origin of this behavior.…”

“…The sample was heat treated at 1350 C and afterward quenched [6]. The temperature dependence of the anisotropy field was measured in a pulsed field using the SPD technique [7].…”

Electromagnetic properties of Ni and La doped strontium hexaferrites in the microwave region

“…4) reveal the decrease of the frequency f { max } of the composite materials with La gradually from 16.7 to 11.8 GHz ( Table 2). The addition of La in hexaferrites is known to correlate with the enhancement of the first order anisotropy constant k 1 through the formation of Fe 2+ cations [40][41][42]. For low La doping in the planar hexaferrite SC the constant k 1 is expected to increase yet remaining negative, thus diminishing the magnitude of the out-of-plane anisotropy H Â (Eq.…”