Photoelectric optical spectroscopy has proven to be of great value in studying the magnetic behavior of the isostructural crystals DyPO4, DyAsO4, and DyVO4. At high resolution absorption lines of these crystals exhibit a five line sub‐structure resulting from various combinations of four thermally flipped nearest‐neighbor moments. The relative intensities of each line are directly proportional to the number of ions having a given near‐neighbor moment configuration. Ordering temperatures for the three crystals have been accurately determined by measuring the relative intensities and determining the point at which there is a sudden change in the short‐range order. Zeeman studies of the three crystals indicate DyAsO4 and DyVO4 are quite different from DyPO4. The moments in DyPO4 are constrained along the c‐axis producing a three dimensional Ising system. On the other hand, the moments of DyAsO4 and DyVO4 are in a plane perpendicular to the c‐axis. Discontinuities occur in the Zeeman splittings when the antiferromagnetic order is destroyed.

1.
R. W. G. Wyckoff, Crystal Structures (Interscience Publishers, Inc., New York, 1965), 2nd ed., Chap. VIII.
2.
John C.
Wright
 and
H. W.
Moos
,
Phys. Lett.
29A
,
495
(
1969
).
Google Scholar
 
3.
J. M.
Ziman
,
Proc. Phys. Soc. (London)
64
,
1108
(
1951
).
Google Scholar
Crossref
Search ADS
 
This content is only available via PDF.
© 1970 The American Institute of Physics.
1970
The American Institute of Physics
You do not currently have access to this content.