Magnetic and dipole moments in indium doped barium hexaferrites

Abstract

Crystal and magnetic structure of the doped BaFe12-xInxO19 samples were refined by the results of investigations using high resolution neutron powder diffraction and vibration sample magnetometry at different temperatures. The refinements were realized in frame of two space groups. The P63/mmc (No 194) centrosymmetric nonpolar and P63mc (No 186) noncentrosymmetric polar space groups were used. The unit cell parameters, ionic coordinates, thermal isotropic factors, occupation positions, bond lengths and bond angles, microstrain values were established. The magnetic and dipole moments were also defined. It is established that the In3+ cations may be located only in the Fe1 -2a and Fe2 -2b crystallographic positions with equal probability for the sample with lowest substitution level x = 0.1. At the x = 1.2 substitution level about half of the In3+ cations occupies the Fe5 -12k positions. For the last sample the remaining half of the In3+ cations is equiprobably located in the Fe1 -2a and Fe2 -2b positions. The spontaneous polarization was established for these compositions at 300 K. It is studied the influence of the type of substitutive cation and structural parameters on the Fe3+(i) -O2--Fe3+(j) (i, j = 1, 2, 3, 4, 5) indirect superexchange interactions with temperature. With substitution level increase the superexchange interactions between the magnetic positions inside and outside the sublattices are broken which leads to a decrease in the value of their magnetic moments.

Investigation of magnetoelectric effect in lead free K0.5Na0.5NbO3-BaFe12O19 novel composite system

“…186). The latter one is a non-centrosymmetric space group and is generally used to describe the crystal structure in order to explain the existence of non-zero spontaneous polarization [18,19]. These ferrites are usually termed as hard ferrites because of their high electrical resistivity, saturation magnetization, coercivity, and mechanical hardness [20].…”

Comparative analysis of efficient Pb dopant in R and R–S blocks of BaFe12O19 structure synthesized by co-precipitation method

“…Such trend was also observed and reported by Teh and Jefferson. It caused the volume of unit cell to reduce [5,13]. Grain size (Fig.…”

“…Researchers have also reported that these properties can be modified by substitution of magnetic and nonmagnetic elements. For this, substitution like Al, Sc and Ga particularly oxide dopants like B 2 O 3 , Si 2 O 3 and CaO not only modify the growth and morphology but also induce fascinating properties [5]. These properties are modified due to microstructural variations in lattice parameters, particle growth and their morphology.…”

A System Engineering Approach Using FMEA and Bayesian Network for Risk Analysis—A Case Study

“…For example, anion-deficient perovskites, as materials with high ionic conductivity and a wide range of temperature stability, are very suitable for fuel cell membranes [19]. Moreover, magneto dielectrics such as hexaferrites: are the materials that are promising for the production of capacitors, which are very necessary for their stable operation [20]. For the stable and steady operation of modern power plants and uninterruptible power systems, it is necessary to provide for their protection against unwanted external electromagnetic radiation.…”