  Mn-based room-temperature ferromagnets attract considerable attention due to
their high ordered Mn moment. We have found that a Pd0.75Mn0.25 alloy with
added B (Pd0.75Mn0.25Bx) shows room-temperature soft ferromagnetism, whereas
the parent Pd0.75Mn0.25 alloy is a spin-glass system. The saturated Mn moment
at room temperature systematically increases to 2.68\muB/Mn as x increases to
0.125. The maximum Curie temperature of 390 K is also realized at an x of
0.125. The experimental results suggest a tunable soft ferromagnetism, which is
governed only by the boron concentration. Our results will pave the way in
chemical control of room-temperature bulk ferromagnetism in Mn compounds based
on the addition of an atom with a small atomic radius.
