We present structural, magnetic, and superconducting behaviors for YBa
2(Cu1-xNix)3Oy with emphasis on x =0.05 given various thermal redox se
quencings, We demonstrate that materials quenched from various air ann
ealing temperatures display an unusual extension of the orthorhombic r
egime compared to unsubstituted materials. In the range of annealing t
emperature near 970K, this is accompanied by volume expansion anomalie
s and slow reoxygenation kinetics probably connected with partial 3+ c
harge localization on Cu. A second volume expansion anomaly occurs nea
r 1080K, probably connected with partial 3+ charge localization on Ni.
These materials can show diamagnetism up to 150K, possibly indicating
a small amount of superconductivity. On reoxygenation at 673K materia
ls undergo a slow transition, first to a paramagnetic-semiconducting s
tate (designated K(o) compounds) and then after several days to a supe
rconducting state similar to conventionally slow cooled oxygenating pr
eparations (OP) which produce T(c) approximately 74K. These supercondu
ctors display anomalous Meissner effects, i.e. the observation of para
magnetism below Tc on small field cooling. This effect is connected wi
th flux trapping in 2 types of regions, namely grain boundaries or loc
al cluster inhomogeneities of the bulk.