Thermodynamic measurements on geometrically frustrated magnets (invited)

Geometrical frustration occurs in antiferromagnetic systems with triangular coordination symmetry. An additional requirement for strong frustration is high local symmetry. We discuss the class of compounds which meet these two requirements and exhibit strong frustration. Novel cooperative effects related to geometrical frustration are discussed for specific compounds, SrCr9pGa12−9pO19, RCuO2 (R=rare earth) and Gd3Ga5O12.