Weak ferromagnetism in a diamagnetically diluted sublattice of Fe3+ ions in solid solutions Y2-xFe1+xTaO7 (x=0-0.2) with pyrochlore-like structure

A series of layered solid solutions Y2-xFe1+xTaO7 (x = 0-0.2) was synthesized and a structural transition (space group R (3) over bar <-> space group P3(1)21) was observed at x = 0.1. In Y2-xFe1+xTaO7, which belongs to both structural types, geometrically frustrated 2D sublattices of kagome-type are formed, in which Fe3+ ions are coupled by short-range antiferromagnetic interactions, and the transition to the spin glass state is observed at T-g similar to 4.3 K. A phenomenon of weak ferromagnetism has been detected, the cause of which is probably a small tilt of the Fe3+ spins due to the Dzyaloshinskii-Moriya antisymmetric superexchange.