The resistivity of anisotropic samples is studied by using the Montgomery
method 
. Assume that a thin,
crystalline specimen is cut to square shape, so that the edges coincide
with the principal axis of the resistivity tensor 
. There are
four contacts at the corners of the sample (Figure 7.1).
Dimensions 
, 
, and (perpendicular to the specimen) 
are
mm and 
mm. In this geometry
two elements of the resistivity tensor, 
and 
, can be
determined by sending current and measuring voltage between various
combinations of the contacts.
Figure 7.1: Sketch of the geometry used in the Montgomery method of
measuring resistivity.
The resistances 
and 
are defined as the ratio of measured voltages
and currents in configurations indicated in the figure. 
and 
are obtained from the data. Use Montgomery's
work to determine and . How would you change the sample
geometry if the resistivity anisotropy is expected to be in the range of
?
Laszlo Mihaly
Thu Oct 31 13:23:11 EST 1996
Cover Page
.