New magnetic phase diagram of (Sr,Ca)2RuO4.

High-T(c) cuprates, iron pnictides, organic BEDT and TMTSF, alkali-doped C(60), and heavy-fermion systems have superconducting states adjacent to competing states exhibiting static antiferromagnetic or spin density wave order. This feature has promoted pictures for their superconducting pairing mediated by spin fluctuations. Sr(2)RuO(4) is another unconventional superconductor which almost certainly has a p-wave pairing.

Muon spin relaxation studies of magnetic-field-induced effects in high-Tc superconductors.

Muon spin relaxation measurements in high transverse magnetic fields [FORMULA: SEE TEXT] revealed strong field-induced quasistatic magnetism in the underdoped and Eu-doped (La,Sr)2CuO4 and La1.875Ba0.125CuO4, existing well above Tc and TN.

Field dependence of the muon spin relaxation rate in MnSi.

Muon spin rotation/relaxation measurements have been performed in the itinerant helical magnet MnSi at ambient pressure and at 8.3 kbar. We have found the following: (a) the spin-lattice relaxation rate 1/T(1) shows divergence as T1T proportional, variant (T-T(c))(beta) with the power beta larger than 1 near T(c); (b) 1/T(1) is strongly reduced in an applied external field B(L) and the divergent behavior near T(c) is completely suppressed at B(L)> or =4000 G.