The Spin Polaron Model and the Comparison with Liquid Helium

2021 ◽  
pp. 271-294
Author(s):  
Ν F Mott
1989 ◽  
Vol 162-164 ◽  
pp. 1499-1500 ◽  
Author(s):  
J. Appel ◽  
P. Hertel ◽  
F. Richter
Keyword(s):  

2004 ◽  
Vol 69 (13) ◽  
Author(s):  
Jayita Chatterjee ◽  
Unjong Yu ◽  
B. I. Min

1990 ◽  
Vol 165 (1) ◽  
pp. 97-106 ◽  
Author(s):  
R.F. Wood ◽  
Mark Mostoller ◽  
J.F. Cooke

Author(s):  
R. E. Worsham ◽  
J. E. Mann ◽  
E. G. Richardson

This superconducting microscope, Figure 1, was first operated in May, 1970. The column, which started life as a Siemens Elmiskop I, was modified by removing the objective and intermediate lenses, the specimen chamber, and the complete vacuum system. The large cryostat contains the objective lens and stage. They are attached to the bottom of the 7-liter helium vessel and are surrounded by two vapor-cooled radiation shields.In the initial operational period 5-mm and 2-mm focal length objective lens pole pieces were used giving magnification up to 45000X. Without a stigmator and precision ground pole pieces, a resolution of about 50-100Å was achieved. The boil-off rate of the liquid helium was reduced to 0.2-0.3ℓ/hour after elimination of thermal oscillations in the cryostat. The calculated boil-off was 0.2ℓ/hour. No effect caused by mechanical or electrical instability was found. Both 4.2°K and 1.7-1.9°K operation were routine. Flux pump excitation and control of the lens were quite smooth, simple, and, apparently highly stable. Alignment of the objective lens proved quite awkward, however, with the long-thin epoxy glass posts used for supporting the lens.


Author(s):  
M.K. Lamvik ◽  
D.A. Kopf ◽  
S.D. Davilla ◽  
J.D. Robertson

Last year we reported1 that there is a striking reduction in the rate of mass loss when a specimen is observed at liquid helium temperature. It is important to determine whether liquid helium temperature is significantly better than liquid nitrogen temperature. This requires a good understanding of mass loss effects in cold stages around 100K.


Sign in / Sign up

Export Citation Format

Share Document