Method for preparing (100) preferred orientation bismuth ferrite thin film

Abstract

The invention relates to a preparation method of a (100) preferred orientation BiFeO3 film, pertaining to the preparation technique of a film material. The invention solves the problems of the prior art for the preparation method of BiFeO3 film, i.e. complicated technique, high cost, high crystallization temperature, low film density, unequal particles distribution, rough surface and no preferred orientation. The preparation steps of the film are that: Fe(NO3)3 and Bi(NO)3 are respectively mixed with acetic acid, and respectively added with glycol solution, and both solutions are mixed and stirred to obtain BiFeO3 sol, and then the BiFeO3 sol is spin-coated to cleaned Pt / Ti / SiO2 / Si substrate, and the substrate is dried, roasted, and is done with crystallization and heat treatment, finally the BiFeO3 film is obtained. The preparation method of the BiFeO3 film of the invention has the advantages of high film quality, (100) preferred orientation, good ferroelectric and ferromagnetic performance, and is suitable for industrialization production.

Description

technical field

[0001] The invention belongs to the field of film materials. Background technique

[0002] The multiferroic material bismuth ferrite (BiFeO 3 ) is a single-phase ferroelectric ferromagnetic material at room temperature. It has broad application prospects in memory, electronic components integrating high capacitance and large inductance, and spintronic devices. BiFeO 3 research has drawn increasing attention.

[0003] BiFeO 3 With G-type antiferromagnetic structure, the bulk material and nanopowder material have little magnetism at room temperature. As the nanoparticle size decreases, the BiFeO 3 The ferromagnetism gradually increases, so the preparation of nano-sized BiFeO with controllable particle size 3 Powder is an excellent way to improve its ferromagnetism; BiFeO produced by existing technology 3 The hysteresis loop squareness of the powder is not good, the residual magnetization is as small as 0.06emu / g, and the coercive force is as large as 200-...

Examples

specific Embodiment approach 1

[0009] Specific embodiment one: the preparation method of a kind of (100) preferred orientation bismuth ferrite film of this embodiment is implemented according to the following steps: a, ferric nitrate and acetic acid are mixed by 1: 10~80 molar ratio, then slowly add concentration is 99.0 ~99.8% ethylene glycol solution, so that the molar ratio of iron ion and ethylene glycol in the solution is 1:5~18, and then stir for 8~12min; b. Mix bismuth subnitrate and acetic acid in a molar ratio of 1:50~400 , then slowly add the ethylene glycol solution with a concentration of 99.0 to 99.8%, so that the molar ratio of bismuth ions and ethylene glycol in the solution is 1: 5 to 18, and then stir for 8 to 12 minutes; c, the prepared by steps a and b The solutions were mixed, and then stirred for 20-40 minutes to obtain BiFeO 3 Sol; d, the Pt / Ti / SiO 2 / Si substrates were ultrasonically cleaned in acetone and absolute ethanol for 4 to 6 minutes, and dried; e, the BiFeO 3 The sol was sp...

specific Embodiment approach 2

[0011] Specific embodiment two: the difference between this embodiment and specific embodiment one is that ferric nitrate and acetic acid are mixed by 1: 40 molar ratio in step a, then slowly add the ethylene glycol solution that concentration is 99.5%, make iron ion in the solution and The molar ratio of ethylene glycol was 1:10, and stirred for another 10 minutes. Other steps and parameters are the same as those in Embodiment 1.

specific Embodiment approach 3

[0012] Specific embodiment three: the difference between this embodiment and specific embodiment one is that in step b, bismuth subnitrate and acetic acid are mixed in a molar ratio of 1:200, and then slowly add a concentration of 99.5% ethylene glycol solution to make bismuth in the solution The molar ratio of ions to ethylene glycol was 1:10, and stirred for another 10 minutes. Other steps and parameters are the same as those in Embodiment 1.

technical field

[0001] The invention belongs to the field of film materials. Background technique

[0002] The multiferroic material bismuth ferrite (BiFeO 3 ) is a single-phase ferroelectric ferromagnetic material at room temperature. It has broad application prospects in memory, electronic components integrating high capacitance and large inductance, and spintronic devices. BiFeO 3 research has drawn increasing attention.

[0003] BiFeO 3 With G-type antiferromagnetic structure, the bulk material and nanopowder material have little magnetism at room temperature. As the nanoparticle size decreases, the BiFeO 3 The ferromagnetism gradually increases, so the preparation of nano-sized BiFeO with controllable particle size 3 Powder is an excellent way to improve its ferromagnetism; BiFeO produced by existing technology 3 The hysteresis loop squareness of the powder is not good, the residual magnetization is as small as 0.06emu / g, and the coercive force is as large as 200-...

Examples

specific Embodiment approach 1

[0009] Specific embodiment one: the preparation method of a kind of (100) preferred orientation bismuth ferrite film of this embodiment is implemented according to the following steps: a, ferric nitrate and acetic acid are mixed by 1: 10~80 molar ratio, then slowly add concentration is 99.0 ~99.8% ethylene glycol solution, so that the molar ratio of iron ion and ethylene glycol in the solution is 1:5~18, and then stir for 8~12min; b. Mix bismuth subnitrate and acetic acid in a molar ratio of 1:50~400 , then slowly add the ethylene glycol solution with a concentration of 99.0 to 99.8%, so that the molar ratio of bismuth ions and ethylene glycol in the solution is 1: 5 to 18, and then stir for 8 to 12 minutes; c, the prepared by steps a and b The solutions were mixed, and then stirred for 20-40 minutes to obtain BiFeO 3 Sol; d, the Pt / Ti / SiO 2 / Si substrates were ultrasonically cleaned in acetone and absolute ethanol for 4 to 6 minutes, and dried; e, the BiFeO 3 The sol was sp...

specific Embodiment approach 2

[0011] Specific embodiment two: the difference between this embodiment and specific embodiment one is that ferric nitrate and acetic acid are mixed by 1: 40 molar ratio in step a, then slowly add the ethylene glycol solution that concentration is 99.5%, make iron ion in the solution and The molar ratio of ethylene glycol was 1:10, and stirred for another 10 minutes. Other steps and parameters are the same as those in Embodiment 1.

specific Embodiment approach 3

[0012] Specific embodiment three: the difference between this embodiment and specific embodiment one is that in step b, bismuth subnitrate and acetic acid are mixed in a molar ratio of 1:200, and then slowly add a concentration of 99.5% ethylene glycol solution to make bismuth in the solution The molar ratio of ions to ethylene glycol was 1:10, and stirred for another 10 minutes. Other steps and parameters are the same as those in Embodiment 1.

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