Rapid sintering preparation method of tl-2212 superconducting thin film

Abstract

The invention discloses a rapid sintering preparation method of Tl-2212 superconducting thin film. Silver foil or gold foil is used to seal and wrap the amorphous precursor film containing thallium and the burning target containing thallium, and the Sintering in the environment. The invention includes four processes including the preparation of a precursor film, the preparation of a thallium source accompanying firing target, the rapid temperature-raising sintering of the precursor film in an argon / oxygen environment, and the oxygen-supplementing heat treatment of a primary sample. Compared with the traditional sintering method, the sintering conditions for growing Tl‑2212 thin films using this technology are not affected by the deposition method of the precursor film, the powder particle size of the starting material of the thallium source accompanying firing target and its preparation method, avoiding the Due to the replacement of the manufacturer's raw materials and the pioneering film deposition method, it is necessary to re-explore the sintering process for a long time. At the same time, the method also greatly reduces the amount of the thallium source accompanying the burning target, shortens the heating and cooling time and constant temperature time, reduces the production cost, and improves the repeatability of the experiment.

Description

technical field

[0001] The invention relates to the field of thallium superconducting thin film materials. More specifically, the present invention relates to a rapid sintering preparation method of Tl-2212 superconducting thin film. Background technique

[0002] Tl 2 Ba 2 CaCu 2 o 8 (Tl-2212) superconducting thin film has a higher critical temperature (T c Up to 110K), high critical current density, and strong moisture resistance are important materials for the development of high-performance high-temperature superconducting electronic devices.

[0003] In the current research on the synthesis of Tl-2212 thin films, the main methods for preparing precursor films include magnetron sputtering, pulsed laser deposition, Aerosol, MOCVD, Sol-gel, etc. The sintering processes of these studies have the following common points: (1) It is necessary to provide a thallium source to accompany the firing target to be sintered together with the precursor film; (2) The heating rate o...

Examples

Embodiment 1

[0035] A kind of rapid sintering preparation method of Tl-2212 superconducting thin film, the substrate is CeO 2 / sapphire, including:

[0036] Step 1. Preparation of thallium-containing amorphous precursor film by sol-gel method: starting materials of thallium, barium, calcium, copper acetate, propionic acid, lactic acid, diethylenetriamine, methanol, etc. Complexing agent and solvent prepare sol; With this sol has CeO 2 Prepare a gel film on the sapphire substrate of the isolation layer, and obtain a precursor film through drying and thermal decomposition processes. The metal ion molar ratio of Tl, Ba, Ca, and Cu of the prepared precursor film is 2.5:2:1:2.2;

[0037] Step 2. Preparation of a thallium-containing burner target: BaO with a metal ion molar ratio of Ba:Ca:Cu=2:2:3 2 , CaO and CuO as starting materials are mixed and ground, kept at a constant temperature of 890-940°C for 4 hours in a flowing oxygen environment, crushed and then ground after cooling, kept at a c...

Embodiment 2

[0042] A kind of rapid sintering preparation method of Tl-2212 superconducting thin film, the substrate is CeO 2 / sapphire, including:

[0043] Step 1. Preparation of thallium-containing amorphous precursor film by sol-gel method: starting materials of thallium, barium, calcium, copper acetate, propionic acid, lactic acid, diethylenetriamine, methanol, etc. Complexing agent and solvent prepare sol; With this sol has CeO 2 Prepare a gel film on the sapphire substrate of the isolation layer, and obtain a precursor film through drying and thermal decomposition processes. The metal ion molar ratio of Tl, Ba, Ca, and Cu of the prepared precursor film is 3.5:2:1:2.6;

[0044] Step 2. Preparation of a thallium-containing burner target: BaO with a metal ion molar ratio of Ba:Ca:Cu=2:2:3 2 , CaO and CuO as starting materials are mixed and ground, kept at a constant temperature of 890-940°C for 8 hours in a flowing oxygen environment, crushed and then ground after cooling, kept at a c...

Embodiment 3

[0049] A kind of rapid sintering preparation method of Tl-2212 superconducting film, substrate is lanthanum aluminate, comprising:

[0050] Step 1. Preparation of an amorphous precursor film containing thallium: BaO with a metal ion molar ratio of Ba:Ca:Cu=2.4:1:2.2 2 or BaO, CaO or CaCO 3 Mix and grind with CuO as the starting material, keep the temperature at 890-940°C for 6h in the flowing oxygen environment, add Tl 2 o 3 Mix and grind the tablets so that the molar ratio of Tl and Ca is Tl:Ca=2.6:1, put them into a sealed crucible, put them together in a sealed quartz tube, and keep the temperature at 840-860°C for 4.5h in a flowing oxygen environment. After cooling, the sputtering target is obtained; radio frequency magnetron sputtering is used for the sputtering target, and the sputtering gas is high-purity Ar or Ar / O 2 Mixed gas, the sputtering pressure is 2.2-6Pa, and the sputtering power is 45W; the molar ratio of Tl, Ba, Ca, and Cu metal ions in the prepared precur...

technical field

[0001] The invention relates to the field of thallium superconducting thin film materials. More specifically, the present invention relates to a rapid sintering preparation method of Tl-2212 superconducting thin film. Background technique

[0002] Tl 2 Ba 2 CaCu 2 o 8 (Tl-2212) superconducting thin film has a higher critical temperature (T c Up to 110K), high critical current density, and strong moisture resistance are important materials for the development of high-performance high-temperature superconducting electronic devices.

[0003] In the current research on the synthesis of Tl-2212 thin films, the main methods for preparing precursor films include magnetron sputtering, pulsed laser deposition, Aerosol, MOCVD, Sol-gel, etc. The sintering processes of these studies have the following common points: (1) It is necessary to provide a thallium source to accompany the firing target to be sintered together with the precursor film; (2) The heating rate o...

Examples

Embodiment 1

[0035] A kind of rapid sintering preparation method of Tl-2212 superconducting thin film, the substrate is CeO 2 / sapphire, including:

[0036] Step 1. Preparation of thallium-containing amorphous precursor film by sol-gel method: starting materials of thallium, barium, calcium, copper acetate, propionic acid, lactic acid, diethylenetriamine, methanol, etc. Complexing agent and solvent prepare sol; With this sol has CeO 2 Prepare a gel film on the sapphire substrate of the isolation layer, and obtain a precursor film through drying and thermal decomposition processes. The metal ion molar ratio of Tl, Ba, Ca, and Cu of the prepared precursor film is 2.5:2:1:2.2;

[0037] Step 2. Preparation of a thallium-containing burner target: BaO with a metal ion molar ratio of Ba:Ca:Cu=2:2:3 2 , CaO and CuO as starting materials are mixed and ground, kept at a constant temperature of 890-940°C for 4 hours in a flowing oxygen environment, crushed and then ground after cooling, kept at a c...

Embodiment 2

[0042] A kind of rapid sintering preparation method of Tl-2212 superconducting thin film, the substrate is CeO 2 / sapphire, including:

[0043] Step 1. Preparation of thallium-containing amorphous precursor film by sol-gel method: starting materials of thallium, barium, calcium, copper acetate, propionic acid, lactic acid, diethylenetriamine, methanol, etc. Complexing agent and solvent prepare sol; With this sol has CeO 2 Prepare a gel film on the sapphire substrate of the isolation layer, and obtain a precursor film through drying and thermal decomposition processes. The metal ion molar ratio of Tl, Ba, Ca, and Cu of the prepared precursor film is 3.5:2:1:2.6;

[0044] Step 2. Preparation of a thallium-containing burner target: BaO with a metal ion molar ratio of Ba:Ca:Cu=2:2:3 2 , CaO and CuO as starting materials are mixed and ground, kept at a constant temperature of 890-940°C for 8 hours in a flowing oxygen environment, crushed and then ground after cooling, kept at a c...

Embodiment 3

[0049] A kind of rapid sintering preparation method of Tl-2212 superconducting film, substrate is lanthanum aluminate, comprising:

[0050] Step 1. Preparation of an amorphous precursor film containing thallium: BaO with a metal ion molar ratio of Ba:Ca:Cu=2.4:1:2.2 2 or BaO, CaO or CaCO 3 Mix and grind with CuO as the starting material, keep the temperature at 890-940°C for 6h in the flowing oxygen environment, add Tl 2 o 3 Mix and grind the tablets so that the molar ratio of Tl and Ca is Tl:Ca=2.6:1, put them into a sealed crucible, put them together in a sealed quartz tube, and keep the temperature at 840-860°C for 4.5h in a flowing oxygen environment. After cooling, the sputtering target is obtained; radio frequency magnetron sputtering is used for the sputtering target, and the sputtering gas is high-purity Ar or Ar / O 2 Mixed gas, the sputtering pressure is 2.2-6Pa, and the sputtering power is 45W; the molar ratio of Tl, Ba, Ca, and Cu metal ions in the prepared precur...

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