  beta-YbAlB4 is a heavy fermion superconductor that exhibits a quantum
criticality without tuning at zero field and under ambient pressure. We have
succeeded in substituting Fe for Al in beta-YbAlB4 as well as the polymorphous
compound alpha-YbAlB4, which in contrast has a heavy Fermi liquid ground state.
Full structure determination by single crystal X-ray diffraction confirmed no
change in crystal structure for both alpha- and beta-YbAlB4, in addition to
volume contraction with Fe substitution. Our measurements of the magnetization
and specific heat indicate that both alpha-YbAl0.93Fe0.07B4 and
beta-YbAl0.94Fe0.06B4 exhibit a magnetic order, most likely of a canted
antiferromagnetic type, at $7\sim 9$ K. The increase in the entropy as well as
the decrease in the antiferromagnetic Weiss temperature with the Fe
substitution in both systems indicates that the chemical pressure due to the Fe
substitution suppresses the Kondo temperature and induces the magnetism.
