  A study of the dependence of the heat capacity Cp(alpha) on field angle in
LuNi2B2C reveals an anomalous disorder effect. For pure samples, Cp(alpha)
exhibits a fourfold variation as the field H < Hc2 is rotated in the [001]
plane, with minima along <100> (alpha = 0). A slightly disordered sample,
however, develops anomalous secondary minima along <110> for H > 1 T, leading
to an 8-fold pattern. The anomalous pattern is discussed in terms of coexisting
superconducting gap anisotropy and non-local effects.
