Concept explainers
The magnetic field created by a dipole has a strength of approximately
(a) Estimate the strength of the magnetic field at the location of a dipole, due to its neighboring dipoles. This is the effective field strength even when there is no externally applied field.
(b) If a magnetic cooling experiment using this material begins with field strength of 1 T, by about what factor will the temperature decrease when the external field is turned off?
(c) Estimate the temperature at which the entropy of this material rises most steeply as a function of temperature, in the absence of an externally applied field.
(d) If the final temperature in a cooling experiment is significantly less than the temperature you found in part (c), the material ends up in a state where
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