Searching for magnetic frustration-like properties in tetrahedral spin systems Cu2Te2O5(Br1-xClx)2

The magnetic frustration in pure and substitutionally disordered compounds from the Cu2Te2O5(Br1-xClx)2 (x=1, 0.75, 0.5, 0) family of low-dimensional quantum magnets was studied experimentally by the methods of zero-field-cooled (zfc) versus field-cooled (fc) DC magnetic susceptibilities, frequency-dependent AC susceptibility and DC thermoremanent magnetization (TRM) decay. The absence of zfc-fc susceptibility splitting, frequency-independence of the AC susceptibility and zero TRM down to the temperature 2K, that is much below the temperatures of spin ordering in these compounds, demonstrate that the spin system is different from classical magnetically frustrated systems-site-disordered spin glasses and geometrically frustrated pure antiferromagnets