Glycine-doped MgB2 superconductor with high critical current density and preparation method thereof

Abstract

The invention relates to a glycine-doped MgB2 superconductor with high critical current density and a preparation method thereof. The preparation method of the glycine-doped MgB2 superconductor includes fully mixing Mg powder, B powder and glycine particles, and obtaining mixed powder of MgB2+Gly of 2-8%; pressing the mixed powder into cylindrical slices under the pressure of 2-10MPa, and placingthe slices in a high-temperature differential scanning calorimeter or a pipe-shaped sintering furnace to carry out sintering; continuously heating at a heating rate of 5-20 DEG C / min to 750-850 DEG C, sintering and keeping warm for 0.5-1h, and cooling to the room temperature at a cooling speed of 30-40 DEG C / min. On the premise that the superconducting transition temperature Tc is not reduced to the greatest extent, novel carbon-containing compound glycine doping is adopted to achieve C replacement effect, and the high-performance MgB2 superconductor is obtained. The shortcoming that traditional C doping reduces the critical current density under a low field is overcome, the critical current density is improved under the whole magnetic field, and a superconductor with superior superconductivity is obtained.

Description

technical field

[0001] The invention belongs to the technical field of superconductivity, in particular to a high critical current density glycine-doped MgB 2 Superconductor and preparation method, thereby increasing the critical current density. Background technique

[0002] Since 1911 H.K.Onnes of Leiden University in the Netherlands [1] After discovering the superconductivity of mercury, people have been unremittingly exploring this phenomenon, and put forward the microscopic theory of superconductivity (BCS theory). Since then, superconducting technology has been applied by humans and continued to be studied in depth, and higher superconducting transition temperatures (T c ) of the substance. In January 2001, Akimitsu Jun of Japan announced that the research team he led had discovered the intermetallic compound superconductor with the highest critical temperature so far—magnesium diboride (MgB 2 ), its superconducting transition temperature reaches 39K [2] , even ex...

Examples

example 1

[0018] Weigh Mg powder and B powder according to the atomic ratio of 1:2, then add glycine with a mass fraction of 2%, and grind it in an agate mortar for 30 minutes to make it fully mixed to obtain MgB 2 +2wt% Gly mixed powder. Press the mixed powder into a cylindrical sheet under a pressure of 2MPa, and then put it into a high-temperature differential scanning calorimeter or a tube sintering furnace for sintering; continuously heat at a heating rate of 5°C / min to 750°C for sintering and keep it warm 0.5 hours, and then lowered to room temperature at a cooling rate of 30°C / min.

example 2

[0020] Weigh Mg powder and B powder according to the atomic ratio of 1:2, then add glycine with a mass fraction of 5%, and grind it in an agate mortar for 30 minutes to make it fully mixed to obtain MgB 2 +5wt% Gly mixed powder. Press the mixed powder into a cylindrical sheet under a pressure of 5 MPa, and then put it into a high-temperature differential scanning calorimeter or a tube sintering furnace for sintering; continuously heat at a heating rate of 10°C / min to 800°C for sintering and keep it warm 0.8 hours, and then cooled down to room temperature at a cooling rate of 35°C / min.

example 3

[0022] Weigh Mg powder and B powder according to the atomic ratio of 1:2, then add glycine with a mass fraction of 8%, and grind it in an agate mortar for 30 minutes to make it fully mixed to obtain MgB 2 +8wt% Gly mixed powder. Press the mixed powder into a cylindrical sheet under a pressure of 10MPa, and then put it into a high-temperature differential scanning calorimeter or a tube sintering furnace for sintering; continuously heat at a heating rate of 20°C / min to 800°C for sintering and keep it warm 1 hour, and then cooled down to room temperature at a cooling rate of 40°C / min.

[0023] The effect description is as follows:

[0024] Weigh the Mg powder and B powder according to the atomic ratio of 1:2, then dope the glycine particles with a mass fraction of 2-8%, and grind them in an agate mortar for 30 minutes to make them fully mixed to obtain MgB 2 +(2~8)% Gly mixed powder. Press the mixed powder into a cylindrical sheet under a pressure of 2-10MPa, and then put it i...

technical field

[0001] The invention belongs to the technical field of superconductivity, in particular to a high critical current density glycine-doped MgB 2 Superconductor and preparation method, thereby increasing the critical current density. Background technique

[0002] Since 1911 H.K.Onnes of Leiden University in the Netherlands [1] After discovering the superconductivity of mercury, people have been unremittingly exploring this phenomenon, and put forward the microscopic theory of superconductivity (BCS theory). Since then, superconducting technology has been applied by humans and continued to be studied in depth, and higher superconducting transition temperatures (T c ) of the substance. In January 2001, Akimitsu Jun of Japan announced that the research team he led had discovered the intermetallic compound superconductor with the highest critical temperature so far—magnesium diboride (MgB 2 ), its superconducting transition temperature reaches 39K [2] , even ex...

Examples

example 1

[0018] Weigh Mg powder and B powder according to the atomic ratio of 1:2, then add glycine with a mass fraction of 2%, and grind it in an agate mortar for 30 minutes to make it fully mixed to obtain MgB 2 +2wt% Gly mixed powder. Press the mixed powder into a cylindrical sheet under a pressure of 2MPa, and then put it into a high-temperature differential scanning calorimeter or a tube sintering furnace for sintering; continuously heat at a heating rate of 5°C / min to 750°C for sintering and keep it warm 0.5 hours, and then lowered to room temperature at a cooling rate of 30°C / min.

example 2

[0020] Weigh Mg powder and B powder according to the atomic ratio of 1:2, then add glycine with a mass fraction of 5%, and grind it in an agate mortar for 30 minutes to make it fully mixed to obtain MgB 2 +5wt% Gly mixed powder. Press the mixed powder into a cylindrical sheet under a pressure of 5 MPa, and then put it into a high-temperature differential scanning calorimeter or a tube sintering furnace for sintering; continuously heat at a heating rate of 10°C / min to 800°C for sintering and keep it warm 0.8 hours, and then cooled down to room temperature at a cooling rate of 35°C / min.

example 3

[0022] Weigh Mg powder and B powder according to the atomic ratio of 1:2, then add glycine with a mass fraction of 8%, and grind it in an agate mortar for 30 minutes to make it fully mixed to obtain MgB 2 +8wt% Gly mixed powder. Press the mixed powder into a cylindrical sheet under a pressure of 10MPa, and then put it into a high-temperature differential scanning calorimeter or a tube sintering furnace for sintering; continuously heat at a heating rate of 20°C / min to 800°C for sintering and keep it warm 1 hour, and then cooled down to room temperature at a cooling rate of 40°C / min.

[0023] The effect description is as follows:

[0024] Weigh the Mg powder and B powder according to the atomic ratio of 1:2, then dope the glycine particles with a mass fraction of 2-8%, and grind them in an agate mortar for 30 minutes to make them fully mixed to obtain MgB 2 +(2~8)% Gly mixed powder. Press the mixed powder into a cylindrical sheet under a pressure of 2-10MPa, and then put it i...

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