CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2021-0013468, filed on Jan. 29, 2021, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

1. Field

The present disclosure relates to dielectric materials, preparation methods thereof, and devices including the same.

2. Description of the Related Art

In accordance with the continuing demand for miniaturization and higher capacity of electronic products, capacitors having a smaller size and higher capacity compared to capacitors of the related art are required. In order to implement capacitors having a smaller size and higher capacity, there is a need for dielectric materials that can provide further improved dielectric properties.

To manufacture a multi-layered ceramic capacitor (MLCC), which is a type of small-size, high-capacity capacitor, dielectric layers need to be made thin. This inevitably induces a rapid increase in an electric field, which leads to a reduction in spontaneous polarization of dielectrics, and consequently, a remarkable drop in permittivity. In addition, the need for a high-temperature dielectric material for use in high value-added MLCC for vehicles or special purposes is gradually increasing. However, a dielectric material that simultaneously satisfies a high permittivity (400 or greater) and a high resistivity (>1.0e12 ohm*cm) is absent in the related art.

SUMMARY

Provided is a high-temperature dielectric material that has excellent temperature characteristics while simultaneously satisfying a high permittivity and a high resistivity.

Provided is a device including the dielectric material.

Provided is a method of preparing the dielectric material.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure. According to an aspect, provided is a dielectric material including a composite represented by Formula 1.
xAB3.(1−x)(BiaNab)TiO3[Formula 1]

wherein, in Formula 1, A is at least one element selected from among lanthanum group elements, rare earth metal elements, or alkaline earth metal elements, B is at least one element selected from transition metal elements, 0.1≤x≤0.5, 0<a<1, 0<b<1, and a+b=1.

According to another aspect, provided is a device comprising: a first electrode; a second electrode facing the first electrode; and a dielectric layer arranged between the first electrode and the second electrode, wherein the dielectric layer includes the dielectric material described above.

The device may be a capacitor. In the case where the first electrode, the dielectric layer, and the second electrode are sequentially stacked, on the second electrode, the dielectric layer and the second electrode may be repeatedly and alternately stacked.

The capacitor may be a multi-layered capacitor including a plurality of internal electrodes; and dielectric layers alternately stacked between the plurality of internal electrodes.

According to another aspect, provided is a method of preparing a dielectric material including a composite represented by Formula 1, the method comprising: mechanically milling a mixture of an A compound, a B compound, a Bi compound, a Na compound, and a Ti compound; and first heat treatment under an oxidizing atmosphere:
xAB3.(1−x)(BiaNab)TiO3[Formula 1]

wherein, in Formula 1, A is at least one element selected from among lanthanum group elements, rare earth metal elements, and alkaline earth metal elements, B is at least one element selected from transition metal elements, 0.1≤x≤0.5, 0<a<1, 0<b<1, and a+b=1.

