Long range magnetic ordering in the quasi-one-dimensional random-bond antiferromagnet BaCu$_2$(Si$_{1-x}$Ge$_{x}$)$_2$O$_7$ is studied in $mu$SR experiments as a function of disorder strength. Compared to the disorder-free parent materials, the satur
ation ordered moment is found to be considerably reduced. Moreover, even in weakly disordered species, the magnetically ordered state is shown to be highly inhomogeneous. The results are interpreted in terms of weakly coupled random spin chains, governed by the ``infinite randomness`` fixed point.
The disordered antiferromagnet pfn (pfns) is investigated in a wide temperature range by combining Mossbauer spectroscopy and neutron diffraction experiments. It is demonstrated that the magnetic ground state is a {it microscopic} coexistence of anti
ferromagnetic and a spin-glass orders. This speromagnet-like phase features frozen-in short-range fluctuations of the Fe$^{3+}$ magnetic moments that are transverse to the long-range ordered antiferromagnetic spin component.
