nature 2000 torsion
TRANSCRIPT
8/20/2019 Nature 2000 Torsion
http://slidepdf.com/reader/full/nature-2000-torsion 1/4
0 40 80 120
Temperature (K)
a . c . s
u s c e p t i b i l i t y ( a . u . )
MgB2
+5% Ti
+5% Ag
+5% Cu
+5% Mo
+5% Y
+5% Fe
0 5 10 15 20 25 30 35
1.0×105
8.0×104
6.0×104
4.0×104
2.0×104
0
5% Fe
5% Mo
MgB2
5% Cu
5% Y 5% Ti 5% Ag
Temperature (K)
J c ( µ 0 H = 1 T )
( A c m – 2 )
a b
©
2001 Macmillan Magazines Ltd
8/20/2019 Nature 2000 Torsion
http://slidepdf.com/reader/full/nature-2000-torsion 2/4
Storsional angle = 60°
Etorsional angle = 0°
2.9 kcal mol –1
a
b
C–H bond(filled)
C–H antibond(vacant)
Hyperconjugatively stabilized bond
E n e r g y
0
1
2
3
4
5
6
7
8
9
10
0 60 120Torsional angle (degrees)
∆ E ( k c a l m o l – 1 )
–110
–90
–70
–50
–30
–10
10
30
0 60 120
Torsional angle (degrees)
E n e r g y c h a n g e ( k c a l m o l – 1 )
RR
FR
ee
ee
nn
nn
©
2001 Macmillan Magazines Ltd
8/20/2019 Nature 2000 Torsion
http://slidepdf.com/reader/full/nature-2000-torsion 3/4
©
2001 Macmillan Magazines Ltd
8/20/2019 Nature 2000 Torsion
http://slidepdf.com/reader/full/nature-2000-torsion 4/4
a
b
µm0 100 200
©
2001 Macmillan Magazines Ltd