Low-temperature fast powder sintering method for superconductive MgB2 nano particle

Abstract

The invention discloses a low-temperature fast powder sintering method for a superconduct nano-particle MgB2, which comprises the steps: magnesium powder and amorphous boron are mixed according to atomic ratio: Mg:B is equal to 1-1.5:2, then the compound is grinded for 0.3 to 2 hours and is pressed into block under the pressure of 2-7MPa; the block is added into a heating device and is added with argon, and the temperature raises to 980K - 1010K at the speed of 20 - 40K / min, then the temperature lowers to room temperature at the speed of 40 - 50K / min, and the superconduct nano-particle MgB2 is made. The diameter of MgB2 of the invention is about 10 to 20nm; Tc value is up to 38.5K, when the MgB2 nano particles are used for measuring superconducting transition temperature, which can not only maintain superconducting transition temperature close to theoretical value, but also be taken as the center of flux pinning, thereby enhancing critical current density.

Description

technical field

[0001] The invention belongs to the field of superconducting technology and relates to a method for preparing superconducting MgB 2 nanoparticle approach. Background technique

[0002] Superconducting technology is a high-tech field with wide application and great development potential, mainly used in power transmission, motor and generator manufacturing, and military technology (Guo Jiandong, Xu Xiaolin, World Nonferrous Metals 10 (2004) 44.) . Since H.K.Onnes of Leiden University in the Netherlands discovered the superconductivity of mercury in 1911 (V.C.Boriseko, world Scientific 4 (2001) 127.), people have been tirelessly exploring this wonderful phenomenon. After nearly a hundred years of hard work, human beings have made great progress in their understanding of superconductivity, but so far new superconductors continue to be discovered, and people still need to continue to explore.

[0003] Superconducting materials can be divided into two categories...

Examples

Embodiment 1

[0022] A superconducting MgB 2 The low-temperature rapid powder sintering method of nanoparticles is composed of the following steps: magnesium powder (purity 99.5%) and amorphous boron powder (purity 99%) are mixed according to the atomic ratio of Mg: B = 1: 2, and in agate grinding Grind it in a bowl for 1 hour to make it evenly mixed, and then press it under a pressure of 5Mpa to form a cylinder of φ4×2mm, and put the pressed sample into a high-temperature differential scanning calorimeter (NETZSCH DSC 404C Peganus) In the process, argon gas is introduced, and then the temperature program is set as follows: the heating rate is 20K / min, rising to 994K, and directly cooling down to room temperature (25°C) at a cooling rate of 40K / min, that is, a superconducting MgB 2 nanoparticles. Determine the phase composition and crystal morphology in the sample by various detection methods.

Embodiment 2

[0024] A superconducting MgB 2 The low-temperature rapid powder sintering method of nanoparticles is composed of the following steps: magnesium powder (purity 99.5%) and amorphous boron powder (purity 99%) are mixed according to the atomic ratio of Mg: B=1.5: 2, and in agate grinding Grind it in a bowl for 1 hour to make it evenly mixed, and then press it under a pressure of 5Mpa to form a cylinder of φ4×2mm, and put the pressed sample into a high-temperature differential scanning calorimeter (NETZSCH DSC 404C Peganus) In the process, argon is introduced, and then the temperature program is set as follows: the heating rate is 20K / min, rising to 994K, and directly cooling down to room temperature (30°C) at a cooling rate of 40K / min, by changing the atomic ratio of Mg and B. Excess Magnesium Effects on MgB 2The effect of nanoparticle formation and changes in the growth pattern of nanoparticles in the melt.

Embodiment 3

[0026] A superconducting MgB 2 The low-temperature rapid powder sintering method of nanoparticles is composed of the following steps: magnesium powder (purity 99.5%) and amorphous boron powder (purity 99%) are mixed according to the atomic ratio of Mg: B = 1: 2, and in agate grinding Grind in a bowl for 1 hour to make it evenly mixed, and then press it under a pressure of 5Mpa to form a cylinder of φ4×2mm, and put the pressed sample into a high-temperature differential scanning calorimeter (NETZSCH DSC 404C Peganus) In the middle, argon gas is introduced, and then the temperature program is set as follows: the heating rate is 40K / min, rises to 994K, and directly drops to room temperature (20°C) at a cooling rate of 40K / min, and the speed is observed by changing the heating rate. For MgB 2 Effects of nanoparticle formation and changes in morphology.

technical field

[0001] The invention belongs to the field of superconducting technology and relates to a method for preparing superconducting MgB 2 nanoparticle approach. Background technique

[0002] Superconducting technology is a high-tech field with wide application and great development potential, mainly used in power transmission, motor and generator manufacturing, and military technology (Guo Jiandong, Xu Xiaolin, World Nonferrous Metals 10 (2004) 44.) . Since H.K.Onnes of Leiden University in the Netherlands discovered the superconductivity of mercury in 1911 (V.C.Boriseko, world Scientific 4 (2001) 127.), people have been tirelessly exploring this wonderful phenomenon. After nearly a hundred years of hard work, human beings have made great progress in their understanding of superconductivity, but so far new superconductors continue to be discovered, and people still need to continue to explore.

[0003] Superconducting materials can be divided into two categories...

Examples

Embodiment 1

[0022] A superconducting MgB 2 The low-temperature rapid powder sintering method of nanoparticles is composed of the following steps: magnesium powder (purity 99.5%) and amorphous boron powder (purity 99%) are mixed according to the atomic ratio of Mg: B = 1: 2, and in agate grinding Grind it in a bowl for 1 hour to make it evenly mixed, and then press it under a pressure of 5Mpa to form a cylinder of φ4×2mm, and put the pressed sample into a high-temperature differential scanning calorimeter (NETZSCH DSC 404C Peganus) In the process, argon gas is introduced, and then the temperature program is set as follows: the heating rate is 20K / min, rising to 994K, and directly cooling down to room temperature (25°C) at a cooling rate of 40K / min, that is, a superconducting MgB 2 nanoparticles. Determine the phase composition and crystal morphology in the sample by various detection methods.

Embodiment 2

[0024] A superconducting MgB 2 The low-temperature rapid powder sintering method of nanoparticles is composed of the following steps: magnesium powder (purity 99.5%) and amorphous boron powder (purity 99%) are mixed according to the atomic ratio of Mg: B=1.5: 2, and in agate grinding Grind it in a bowl for 1 hour to make it evenly mixed, and then press it under a pressure of 5Mpa to form a cylinder of φ4×2mm, and put the pressed sample into a high-temperature differential scanning calorimeter (NETZSCH DSC 404C Peganus) In the process, argon is introduced, and then the temperature program is set as follows: the heating rate is 20K / min, rising to 994K, and directly cooling down to room temperature (30°C) at a cooling rate of 40K / min, by changing the atomic ratio of Mg and B. Excess Magnesium Effects on MgB 2The effect of nanoparticle formation and changes in the growth pattern of nanoparticles in the melt.

Embodiment 3

[0026] A superconducting MgB 2 The low-temperature rapid powder sintering method of nanoparticles is composed of the following steps: magnesium powder (purity 99.5%) and amorphous boron powder (purity 99%) are mixed according to the atomic ratio of Mg: B = 1: 2, and in agate grinding Grind in a bowl for 1 hour to make it evenly mixed, and then press it under a pressure of 5Mpa to form a cylinder of φ4×2mm, and put the pressed sample into a high-temperature differential scanning calorimeter (NETZSCH DSC 404C Peganus) In the middle, argon gas is introduced, and then the temperature program is set as follows: the heating rate is 40K / min, rises to 994K, and directly drops to room temperature (20°C) at a cooling rate of 40K / min, and the speed is observed by changing the heating rate. For MgB 2 Effects of nanoparticle formation and changes in morphology.

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