Room Temperature Magnetoelectric Effects on Single Slabs of Z-type Hexaferrites

TL;DR

This study demonstrates significant room temperature magnetoelectric effects in Sr Z-type hexaferrite slabs, showing potential for microwave device applications due to electric field-induced magnetization changes.

Contribution

First measurement of room temperature magnetoelectric effects in Sr Z-type hexaferrite with high resistivity, revealing substantial remanence changes under electric fields.

Findings

~18% change in remanence magnetization at 10,000 V/cm

High resistivity achieved by oxygen annealing

Implications for microwave applications at room temperature

Abstract

In this paper, magnetoelectric effects of Sr Z-type hexaferrite, Sr3Fe24Co2O41, at room temperature is measured. The change in remanence magnetization was measured by applying a DC voltage or electric field across a slab of hexaferrite. Changes of ~ 18% in remanence was observed in an electric field of 10,000V/cm implying a similar change in the microwave permeability at frequencies below 3GHz. In these types of measurements high resistivity is critical in order to reduce current flow in the hexaferrite. The resistivity of the hexaferrite was raised to 4.28x10^8 ohm?-cm by annealing under oxygen pressure. The measurements indicate that indeed electric polarization and magnetization changes were induced by the application of magnetic and electric fields, respectively. The implications for microwave applications appear to be very promising at room temperature.