Extremely Polysubstituted Magnetic Material Based on Magnetoplumbite with a Hexagonal Structure: Synthesis, Structure, Properties, Prospects.

Denis Vinnik,Svetlana Gudkova,Darya Sherstyuk,Alexey Trukhanov,Denis Klygach,Dmitry Zherebtsov,Elena Sander,Andrey Starikov,Sergey Taskaev,Maxim Vakhitov,Evgeny Trofimov,Olga Zaitseva,Vladimir Zhivulin

doi:10.3390/nano9040559

Abstract

Crystalline high-entropy single-phase products with a magnetoplumbite structure with grains in the μm range were obtained using solid-state sintering. The synthesis temperature was up to 1400 °C. The morphology, chemical composition, crystal structure, magnetic, and electrodynamic properties were studied and compared with pure barium hexaferrite BaFe12O19 matrix. The polysubstituted high-entropy single-phase product contains five doping elements at a high concentration level. According to the EDX data, the new compound has a formula of Ba(Fe6Ga1.25In1.17Ti1.21Cr1.22Co1.15)O19. The calculated cell parameter values were a = 5.9253(5) Å, c = 23.5257(22) Å, and V = 715.32(9) Å3. The increase in the unit cell for the substituted sample was expected due to the different ionic radius of Ti/In/Ga/Cr/Co compared with Fe3+. The electrodynamic measurements were performed. The dielectric and magnetic permeabilities were stable in the frequency range from 2 to 12 GHz. In this frequency range, the dielectric and magnetic losses were −0.2/0.2. Due to these electrodynamic parameters, this material can be used in the design of microwave strip devices.

Highlights

Starting from 2010 [1], the properties of high-entropy oxide phases have been intensively studied [2,3,4,5,6,7,8,9,10]
Cubic oxide phases formed by divalent metals Mg, Co, Ni, Cu, and Zn [4,7,8], or rare earth metals were studied [9,10]
The following studies on such materials led to the discovery of phases (Mg,Co,Ni,Cu,Zn)1-x-yGayAxO with high-ionic conductivity, which makes them promising for use as solid electrolytes [5] that could be obtained as a thin film [16]

Summary

Introduction

Starting from 2010 [1], the properties of high-entropy oxide phases have been intensively studied [2,3,4,5,6,7,8,9,10]. Two papers describe high-entropy phases with the perovskite structure [14,15]. Some researchers have studied the electrophysical and magnetic properties of high-entropy oxide phases [3,5,6,13,16,17]. The following studies on such materials led to the discovery of phases (Mg,Co,Ni,Cu,Zn)1-x-yGayAxO (with A=Li,Na,K) with high-ionic conductivity, which makes them promising for use as solid electrolytes [5] that could be obtained as a thin film [16]. A recently published paper aimed to generalize the theoretical description of high-entropy phase stability [18]

Methods

Results

Conclusion