A Novel Magneto‐Dielectric Solid Solution Ceramic 0.25LiFe₅O₈–0.75Li₂ZnTi₃O₈ with Relatively High Permeability and Ultra‐Low Dielectric Loss

Abstract

In this study, a 0.25LiFe 5 O 8 -0.75Li 2 ZnTi 3 O 8 solid solution ceramic was developed via the solid-state reaction method. Its phase evolution, microstructure, and sintering behavior were investigated and it was found that the 25 mol.% LiFe 5 O 8 phase is almost fully soluble in Li 2 ZnTi 3 O 8, and only the Li 2 ZnTi 3 O 8 type spinel phase was formed in the 0.25LiFe 5 O 8 -0.75Li 2 ZnTi 3 O 8 ceramic. The ceramic sample sintered at 1050°C for 2 h was found to possess both good magnetic properties and dielectric properties in the frequency range from 1 to 10 MHz, with permeability between 38.2 and 15 and magnetic loss tangent between 0.25 and 0.75, permittivity between 19.6 and 19.3 and dielectric loss tangent between 8 3 10 À3 and 2 3 10 À3 . The sample also possesses good microwave dielectric properties with a relative permittivity of 19.1, a high quality factor (Qf)~11,770 GHz (at 6.84 GHz). The ceramic is a novel magneto-dielectric ceramic with both high permeability and good dielectric properties, which might be a good candidate for the applications in novel electronic devices.H. Jantunen-contributing editor Manuscript No. 31581.

Order–Disorder Phase Transition and Magneto‐Dielectric Properties of (1−x)LiFe5O8–xLi2ZnTi3O8 Spinel‐Structured Solid Solution Ceramics

“…On the basis of the experimental results, different metal cations in cubic spinel show different preference to take A and B sites. The preference of the metal cations in (1− x )LiFe 5 O 8 – x Li 2 ZnTi 3 O 8 to take B sites can be sorted as Zn 2+ < Fe 3+ < Li + < Ti 4+ . According to this, for each chemical formula at a given value of x , the metallic ion position in A and B site can be deduced.…”

“…The experimental data shows that the bulk densities, the permittivity, the permeability, magnetization saturation of the prepared samples are somewhat different between 1050°C and 1100°C. However, for each component of the ceramics, the Q × f values reach a maximum at 1050°C and then decrease sharply with the sintering temperature increasing . For this reason, the samples sintered at 1050°C have been chosen in order to get the best quality factor.…”

“…The polymer‐based composites and the multiphase cofired ceramics are commonly studied among the magneto‐dielectric materials . However, there are some intrinsic drawbacks of the composite samples as mentioned in the previous works . For example, the polymer‐based composites are always limited in applications due to their low melting point and filler concentration.…”

A Novel Magnetodielectric Solid Solution Ceramic 0.4LiFe5O8–0.6Li2MgTi3O8 with Excellent Microwave Dielectric Properties

“…However, for the 0.4LFO–0.6LMT ceramic, with the increase in Li + , Mg 2+ , and Ti 4+ substitutions introduced into LiFe 5 O 8 , a statistical disorder is induced within the structure, disrupting the ordered arrangement of Li + and Fe 3+ in the octahedral B sites. According to the preference of the metal cations to take B site (Fe 3+ < Mg 2+ < Li + < Ti 4+ ), the molecular formula 0.4LFO–0.6LMT can be rewritten as [Fe 2 ] T [Mg 0.6 Li 1.6 Ti 1.8 ] O O 8 while the α‐LFO equals to [Fe 2 ] T [LiFe 3 ] O O 8 , where T refers to the tetrahedron and O refers to the octahedron, respectively. It is obvious that Fe 3+ ions all occupy A sites in 0.4LFO–0.6LMT, and the 1:3 ordering of Li + and Fe 3+ at the B sites has been completely destroyed.…”

Vibrational spectroscopic and crystal chemical analyses of double perovskite Y2MgTiO6 microwave dielectric ceramics

“…There is presently a strong ongoing exploration for materials with relative permittivity values of approximately 20 to meet various device demands. Researchers have developed solid solutions of the (Ca,Bi)(Mo,V)O 4 family, a ZnO–Nb 2 O 5 binary system, 0.25LiFe 5 O 8 –0.75Li 2 ZnTi 3 O 8 , 0.33Li 2 MgTi 3 O 8 –0.67Li 2 TiO 3 , NdNbO 4 –based structures, perovskite‐related structures and initially synthesized Bi 3 NbO 7 , BiSbO 4 , etc., ceramics with interesting properties. Among these materials, perovskite‐related structures have received considerable attention owing to their versatility and phase composition …”