Magnetic correlations in low dimensional systems with varying arrangements of spin topologies

Low-dimensional magnetic systems have been of great interest due to their unconventional, novel, and complex electronic and magnetic properties. Different topologies of spin arrangements, such as quasi-1-D spin chains, triangular, kagome, and square lattices are possible. Structural, electronic, and magnetic properties of such systems strongly depend on the topology. A detailed microscopic understanding of the nature of magnetic ordering of a large variety of low dimensional magnetic systems, such as the Brownmillerite-type bilayered compounds Ca2.5-xLaxSr0.5GaMn2O8, the quasi 2-D spin-1/2 square-lattice system Zn2VO(PO4)2 with J1-J2 exchange interactions, the 2-D geometrically frustrated quantum S = 1/2 square-lattice system (CuBr)Sr2Nb3O10 with J1-J2-J3 exchange interactions, the quasi-1-D spin-1 quantum system Sr1-xCaxNi2V2O8, the 2-D layered Kagome lattice compounds YBaCo4-xFexO7, and the quasi-1D spin chain compounds Ca3Co2-xFexO6 with triangular arrangement of spin-chains has been obtained. In my talk, I will review these results elucidating the microscopic nature of magnetic correlations in such low dimensional spin systems with varying arrangements of spin topologies. The applicability of various theoretical models in explaining magnetic behavior of such low-dimensional systems will be outlined. (author)