Preparation method of bismuth ferrite film

Abstract

The invention discloses a preparation method of a bismuth ferrite film, which comprises the following steps: dissolving an iron-containing inorganic salt and a bismuth-containing inorganic salt in a solvent, and dissolving at a certain temperature until the solution is clear, so as to obtain a transparent reddish brown solution; adding a proper amount of solvent diluent into the obtained solution to obtain a precursor solution; stirring and aging the precursor solution; magnetically stirring the aged precursor solution again, dropwise adding a certain amount of the precursor solution into the container, then adding a proper amount of solvent for dilution again, and controlling the thickness of the bismuth ferrite film through the solution which is diluted to a certain concentration; a substrate for preparing the thin film is cleaned and dried by physical and chemical methods before being used, and the substrate is immersed in a solution diluted to a certain concentration for thin film deposition; and annealing the prepared film to complete crystal structure reforming. The method is convenient to operate, high in yield and capable of rapidly preparing the large-area, high-quality and uniform ultrathin bismuth ferrite film, and plays an important role in promoting device integration and application of the bismuth ferrite film.

Description

technical field

[0001] The invention relates to the technical field of ferroelectric thin film materials, in particular to a preparation method of a bismuth ferrite thin film. Background technique

[0002] Multiferroic materials (multiferroics) refer to the basic properties that contain two or more types of iron in the same phase. The basic properties of these irons include ferroelectricity (antiferroelectricity), ferromagnetism (antiferromagnetism, ferrous magnetism) and ferroelasticity. Bismuth ferrite (BiFeO3, referred to as BFO) is the only single-phase multiferroic material with both ferroelectricity and antiferromagnetism at room temperature, and has a large remnant polarization (-95 C / cm 2 ), high ferroelectric Curie temperature (about 830°C), relatively high antiferromagnetic Neel temperature (about 370°C), small band gap (2.3-2.7eV) and multiferroic properties. Because of the above characteristics, it is considered as the best material that is expected to be appli...

Examples

Embodiment 1

[0030] A kind of preparation method of bismuth ferrite film of the present invention, comprises the steps:

[0031] Step 1, substrate cleaning

[0032] Silicon wafers are selected as the substrate, and the substrate is ultrasonically cleaned with acetone, absolute ethanol and deionized water for 5-10 minutes before use, and finally dried quickly with nitrogen.

[0033] Step 2, preparation of precursor solution

[0034] (1) Mixing an appropriate amount of Fe(NO 3 ) 3 9H 2 O and Bi(NO 3 ) 3 ·5H 2 O (the molar ratio is 1:1.02-1.06), dissolved in ethylene glycol methyl ether, stirred at a temperature of about 15°C until the solution is clear, and the obtained solution is a transparent reddish-brown solution 1;

[0035] (2) Add a small amount of solvent to dilute the solution to obtain a certain concentration (0.5mol / L) of the precursor solution 2, and the solvent for dilution is preferably ethylene glycol methyl ether;

[0036] (3) Place the precursor solution obtained in ...

Embodiment 2

[0044] The preparation method of the bismuth ferrite thin film of this embodiment is different from that of the first embodiment in that no deionized rinse is performed before the annealing, and the thickness of the obtained thin film is about 264 nm.

technical field

[0001] The invention relates to the technical field of ferroelectric thin film materials, in particular to a preparation method of a bismuth ferrite thin film. Background technique

[0002] Multiferroic materials (multiferroics) refer to the basic properties that contain two or more types of iron in the same phase. The basic properties of these irons include ferroelectricity (antiferroelectricity), ferromagnetism (antiferromagnetism, ferrous magnetism) and ferroelasticity. Bismuth ferrite (BiFeO3, referred to as BFO) is the only single-phase multiferroic material with both ferroelectricity and antiferromagnetism at room temperature, and has a large remnant polarization (-95 C / cm 2 ), high ferroelectric Curie temperature (about 830°C), relatively high antiferromagnetic Neel temperature (about 370°C), small band gap (2.3-2.7eV) and multiferroic properties. Because of the above characteristics, it is considered as the best material that is expected to be appli...

Examples

Embodiment 1

[0030] A kind of preparation method of bismuth ferrite film of the present invention, comprises the steps:

[0031] Step 1, substrate cleaning

[0032] Silicon wafers are selected as the substrate, and the substrate is ultrasonically cleaned with acetone, absolute ethanol and deionized water for 5-10 minutes before use, and finally dried quickly with nitrogen.

[0033] Step 2, preparation of precursor solution

[0034] (1) Mixing an appropriate amount of Fe(NO 3 ) 3 9H 2 O and Bi(NO 3 ) 3 ·5H 2 O (the molar ratio is 1:1.02-1.06), dissolved in ethylene glycol methyl ether, stirred at a temperature of about 15°C until the solution is clear, and the obtained solution is a transparent reddish-brown solution 1;

[0035] (2) Add a small amount of solvent to dilute the solution to obtain a certain concentration (0.5mol / L) of the precursor solution 2, and the solvent for dilution is preferably ethylene glycol methyl ether;

[0036] (3) Place the precursor solution obtained in ...

Embodiment 2

[0044] The preparation method of the bismuth ferrite thin film of this embodiment is different from that of the first embodiment in that no deionized rinse is performed before the annealing, and the thickness of the obtained thin film is about 264 nm.

Images