J. Freudenberger et al., Diluted and concentrated isoelectronic substitutional effects in superconducting RxY1-xNi2B2C compounds, J L TEMP PH, 117(5-6), 1999, pp. 1623-1627
The suppression of superconductivity of pseudo-quaternary RxY1-xNi2B2C comp
ounds in the dilute limit was Sound to be mainly caused by magnetic pair-br
eaking in the case of the heavy rare-earth elements (R = Tm, Er, Ho, Dy, Tb
, Gd) and by lattice distortions in the case of the light rare-earth elemen
ts (R = Pr, Nd) resulting from the large difference of the ionic radii betw
een the Y host ions and the R impurity ones.