The samples were characterized using X-ray diffractometry, scanning electron microscopy and differential thermal analysis. The dependence of the magnetic alternating-current susceptibility and resistivity upon temperature was determined. A dependence of MgB2 superconducting properties upon the thermal profiles used in the manufacturing stage of the compound was demonstrated. A correlation was found between the change of the superconducting capabilities and the structure of the final material.

Dependence of the Structural and Superconducting Properties of MgB2 Pellets on the Thermal Profiles of the Manufacturing Process. J.Petrou, E.Hristoforou, D.Stamopoulos, A.Valasiadis: Journal of Materials Processing Technology, 2005, 161[1-2], 33-5

 

Table 2

Thermodynamic Functions of MgB2

 

Temperature (K)

Cp (cal/deg.mol)

S0 (cal/deg.mol)

20

0.014

0.005

25

0.036

0.010

30

0.060

0.015

35

0.095

0.027

40

0.150

0.045

45

0.222

0.070

50

0.337

0.102

60

0.630

0.183

70

1.094

0.318

80

1.595

0.491

90

2.125

0.711

100

2.670

0.962

110

3.241

1.238

120

3.823

1.549

130

4.430

1.872

140

5.050

2.231

150

5.630

2.650

160

6.200

2.980

170

6.720

3.370