Recent progress in the understanding of the complex magnetic properties of
the family of rare-earth strontium oxides, SrLn2O4, is reviewed. These
compounds consisting of hexagons and triangles are affected by geometrical
frustration and therefore exhibit its characteristic features, such as a
significant reduction of magnetic ordering temperatures and complex phase
diagrams in an applied field. Some of the observed features appear to be rather
remarkable even in the context of the unusual behavior associated with
geometrically frustrated magnetic systems. Of particular interest is the
coexistence at the lowest temperature of different magnetic structures
(exhibiting either long or short-range order) characterized by different
propagation vectors in materials without significant chemical or structural
disorder.Comment: Review Articl
