A common-path Zeeman interferometry technique has been developed and a
pplied for the measurements of refractive index gradients of the fluid
s to an accuracy of Delta n = 9.4 x 10(-9). The Zeeman interferometry
technique has over 100 times better resolution than the other interfer
ometry techniques. A linear refractive index profile of the solution a
t the interface of the growing L-arginine phosphate crystal from solut
ion was measured successfully using a scanning Zeeman interferometry t
echnique.