CEC-ICMC 2015 - Timetable, Abstracts and Presentations

Obatining of Massive MgB2 superconductor

Not scheduled

15m

JW Marriott Starr Pass Resort

Contributed Oral Presentation ICMC-04 - MgB2 Processing and Properties

Speakers

Dr Guram Bokuchava (Sokhumi Ilia Vekua Institute of Physics and Technology)Ms Natia Jalagonia (Sokhumi Ilia Vekua Institute of Physics and Technology)Dr Roin Chedia (Sokhumi Ilia Vekua Institute of Physics and Technology)Mrs Tinatin Kuchukhidze (Sokhumi Ilia Vekua Institue of Physics and Technology)

Description

Magnesium diboride bulk superconductor samples (targets) with a diameter >50 mm has been obtained in an induction furnace, using hot press and spark-plasma synthesis methods. Those methods enable to obtain small diameter (up to <25 mm) samples without any difficulties by gradual temperature increase 20-10500C during 5-12 minutes. Increased diameter (>50 mm) of the samples reveal a number of problems. Despite the fact that big diameter samples phase content is like small ones, their porosity is increased and in some cases samples crashed wholly. Homogenization and activation of powders were conducted in a planetary nano-mill by WC balls in an inert area. Pressing of the obtained powders was conducted in an argon atmosphere. MgB2 nonstoichiometric powders contained excess boron and magnesium. Magnesium hydride was used as source of excess magnesium, which is fragile compound and easy to grind in nano-mill. It decomposites with metallic magnesium and hydrogen up to 280°C temperature. Powders systems of MgB2-Mg, MgB2-MgH2,MgB2-B has been pressed at the pressure p=100 MPa. The targets were cylinders with diameters of 10-52mm and height of 5-15mm. Phase content of the obtained targets were established by XRD method after dry polishing in Glove Box. Superconducting characteristic of the obtained samples were measured by vibrational magnetometer. The superconducting transition with an onset at 39K was observed in a good agreement with the results of the other groups obtained on samples prepared by conventional techniques.