Preparation method of BIT-Fe multiferroic ferroelectric ceramic

Abstract

The invention provides a preparation method of a BIT-Fe multiferroic ferroelectric ceramic. Bi2O3 (bismuth oxide), TiO2 (titanium dioxide) and Fe2O3 (ferric oxide) are used as raw materials, and the BIT-Fe multiferroic ferroelectric ceramic with a pure phase is prepared by a solid phase method, so that the ceramic has ferroelectricity, ferromagnetism and especially opposite ferromagnetism at the same time, and the BIT-Fe multiferroic ferroelectric ceramic has wide application prospects in spintronics and other fields. The preparation method disclosed by the invention has the characteristics that the preparation technology is simple, the preparation technology meets the requirements of industrialized production, and doped substances are simple and easy to obtain, so that the BIT ceramic has a multiferroic characteristic, the purity of the prepared ceramic is high, the prepared ceramic does not include other sundries or hazardous compounds, such as Pb (plumbum), and the prepared ceramic meets the manufacturing requirements of green electronic materials.

Description

technical field

[0001] The invention relates to a preparation method of ferroelectric ceramics, in particular to a preparation method of BIT-Fe multiferroic ferroelectric ceramics. Background technique

[0002] Bismuth titanate (Bi 4 Ti 3 o 12 ) and its doped ferroelectric materials have attracted extensive attention due to their high resistivity, good fatigue resistance, high dielectric constant, and environmental friendliness. Structurally, Bi 4 Ti 3 o 12 Belonging to the Aurivillius layered structure, two adjacent (Bi 2 o 2 ) 2+ There are three layers in between (Bi 2 Ti 3 o 10 ) 2- structure. In terms of electricity, Bi 4 Ti 3 o 12 (BIT) is a typical bismuth layer structure ferroelectric compound with m=3. Above the Curie point (T c =675°C) above the temperature, its crystal belongs to the paraelectric phase structure of the tetragonal system; c The timing corresponds to the monoclinic ferroelectric phase, which is an m-point group, close to the orthor...

Examples

Embodiment 1

[0028] Step 1: Put Bi 2 o 3 、TiO 2 and Fe 2 o 3 Accurately weigh the materials according to the molar ratio of 2:3:0.01. After mixing, powder A is obtained. According to the mass ratio, powder A: zirconia ball stone: distilled water = 1:3:1. After mixing, ball mill in a ball mill tank for 5 hours;

[0029] Step 2: Dry the powder A after ball milling in step 1 in a constant temperature oven at 70°C for 15 hours, grind and briquette, and then pre-fire it in a muffle furnace. The heating and cooling rates are 3-4°C / min, firstly from room temperature to 400°C, and hold for 10 minutes; then from 400°C to 810°C, and hold for 2.5 hours; then cool down from 810°C to 400°C; finally cool with the furnace to room temperature; grind again to obtain Bi 4 Ti 3 o 12 -Fe 2 o 3 Powder;

[0030] Step 3: Bi according to mass ratio 4 Ti 3 o 12 -Fe 2 o 3 Powder: zirconia ball stone: distilled water = 1:3:1, the Bi obtained in step 2 4 Ti 3 o 12 -Fe 2 o 3 The powder is ball mill...

Embodiment 2

[0032] Step 1: Put Bi 2 o 3 、TiO 2 and Fe 2 o 3 Accurately weigh the materials according to the molar ratio of 2:4:0.1. After mixing, powder A is obtained. According to the mass ratio, powder A: zirconia ball stone: distilled water = 1:5:1.1. After mixing, ball mill in a ball mill tank for 8 hours;

[0033] Step 2: Dry the powder A after ball milling in step 1 in a thermostat at 75°C for 8 hours, grind and briquette, and pre-fire in a muffle furnace. The pre-fire conditions are: in the muffle furnace, follow the temperature The heating and cooling rates are 4~5°C / min respectively. First, the temperature is raised from room temperature to 400°C and held for 10 minutes; then the temperature is raised from 400°C to 820°C and held for 3 hours; Room temperature; regrind to get Bi 4 Ti 3 o 12 -Fe 2 o 3 Powder;

[0034] Step 3: Bi according to mass ratio 4 Ti 3 o 12 -Fe 2 o 3 Powder: zirconia ball stone: distilled water = 1:8:1.2, the Bi obtained in step 2 4 Ti 3 o ...

Embodiment 3

[0036] Step 1: Put Bi 2 o 3 、TiO 2 and Fe 2 o 3 Accurately weigh the materials according to the molar ratio of 3:3:0.06. After mixing, powder A is obtained. According to the mass ratio, powder A: zirconia ball stone: distilled water = 1:1:1.2. After mixing, ball mill in a ball mill tank for 6 hours;

[0037] Step 2: Dry the powder A after ball milling in step 1 in an incubator at 80°C for 12 hours. After grinding and briquetting, pre-fire in a muffle furnace. The pre-fire conditions are: in the muffle furnace, follow the temperature rise The heating and cooling rates are respectively 5-6°C / min. First, the temperature is raised from room temperature to 400°C and kept for 10 minutes; then the temperature is raised from 400°C to 800°C and kept for 2.8 hours; then the temperature is lowered from 800°C to 400°C; to room temperature; grind again to obtain Bi 4 Ti 3 o 12 -Fe 2 o 3 Powder;

[0038] Step 3: Bi according to mass ratio 4 Ti 3 o 12 -Fe 2 o 3 Powder: zirconi...

technical field

[0001] The invention relates to a preparation method of ferroelectric ceramics, in particular to a preparation method of BIT-Fe multiferroic ferroelectric ceramics. Background technique

[0002] Bismuth titanate (Bi 4 Ti 3 o 12 ) and its doped ferroelectric materials have attracted extensive attention due to their high resistivity, good fatigue resistance, high dielectric constant, and environmental friendliness. Structurally, Bi 4 Ti 3 o 12 Belonging to the Aurivillius layered structure, two adjacent (Bi 2 o 2 ) 2+ There are three layers in between (Bi 2 Ti 3 o 10 ) 2- structure. In terms of electricity, Bi 4 Ti 3 o 12 (BIT) is a typical bismuth layer structure ferroelectric compound with m=3. Above the Curie point (T c =675°C) above the temperature, its crystal belongs to the paraelectric phase structure of the tetragonal system; c The timing corresponds to the monoclinic ferroelectric phase, which is an m-point group, close to the orthor...

Examples

Embodiment 1

[0028] Step 1: Put Bi 2 o 3 、TiO 2 and Fe 2 o 3 Accurately weigh the materials according to the molar ratio of 2:3:0.01. After mixing, powder A is obtained. According to the mass ratio, powder A: zirconia ball stone: distilled water = 1:3:1. After mixing, ball mill in a ball mill tank for 5 hours;

[0029] Step 2: Dry the powder A after ball milling in step 1 in a constant temperature oven at 70°C for 15 hours, grind and briquette, and then pre-fire it in a muffle furnace. The heating and cooling rates are 3-4°C / min, firstly from room temperature to 400°C, and hold for 10 minutes; then from 400°C to 810°C, and hold for 2.5 hours; then cool down from 810°C to 400°C; finally cool with the furnace to room temperature; grind again to obtain Bi 4 Ti 3 o 12 -Fe 2 o 3 Powder;

[0030] Step 3: Bi according to mass ratio 4 Ti 3 o 12 -Fe 2 o 3 Powder: zirconia ball stone: distilled water = 1:3:1, the Bi obtained in step 2 4 Ti 3 o 12 -Fe 2 o 3 The powder is ball mill...

Embodiment 2

[0032] Step 1: Put Bi 2 o 3 、TiO 2 and Fe 2 o 3 Accurately weigh the materials according to the molar ratio of 2:4:0.1. After mixing, powder A is obtained. According to the mass ratio, powder A: zirconia ball stone: distilled water = 1:5:1.1. After mixing, ball mill in a ball mill tank for 8 hours;

[0033] Step 2: Dry the powder A after ball milling in step 1 in a thermostat at 75°C for 8 hours, grind and briquette, and pre-fire in a muffle furnace. The pre-fire conditions are: in the muffle furnace, follow the temperature The heating and cooling rates are 4~5°C / min respectively. First, the temperature is raised from room temperature to 400°C and held for 10 minutes; then the temperature is raised from 400°C to 820°C and held for 3 hours; Room temperature; regrind to get Bi 4 Ti 3 o 12 -Fe 2 o 3 Powder;

[0034] Step 3: Bi according to mass ratio 4 Ti 3 o 12 -Fe 2 o 3 Powder: zirconia ball stone: distilled water = 1:8:1.2, the Bi obtained in step 2 4 Ti 3 o ...

Embodiment 3

[0036] Step 1: Put Bi 2 o 3 、TiO 2 and Fe 2 o 3 Accurately weigh the materials according to the molar ratio of 3:3:0.06. After mixing, powder A is obtained. According to the mass ratio, powder A: zirconia ball stone: distilled water = 1:1:1.2. After mixing, ball mill in a ball mill tank for 6 hours;

[0037] Step 2: Dry the powder A after ball milling in step 1 in an incubator at 80°C for 12 hours. After grinding and briquetting, pre-fire in a muffle furnace. The pre-fire conditions are: in the muffle furnace, follow the temperature rise The heating and cooling rates are respectively 5-6°C / min. First, the temperature is raised from room temperature to 400°C and kept for 10 minutes; then the temperature is raised from 400°C to 800°C and kept for 2.8 hours; then the temperature is lowered from 800°C to 400°C; to room temperature; grind again to obtain Bi 4 Ti 3 o 12 -Fe 2 o 3 Powder;

[0038] Step 3: Bi according to mass ratio 4 Ti 3 o 12 -Fe 2 o 3 Powder: zirconi...

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