Title: GdPtPb: A non collinear antiferromagnet with distorted Kagomé lattice,
Abstract: In the spirit of searching for Gd-based, frustrated, rare earth magnets, we
have found antiferomagnetism (AF) in GdPtPb which crystallizes in the
ZrNiAl-type structure that has a distorted Kagomé lattice of Gd-triangles.
Single crystals were grown and investigated using structural, magnetic,
transport and thermodynamic measurements. GdPtPb orders antiferromagnetically
at 15.5 K arguably with a planar, non-collinear structure. The high temperature
magnetic susceptibility data reveal an "anti-frustration" behavior having a
frustration parameter, $|f|$ = $|\Theta|$/ $T_N$ = 0.25, which can be explained
by mean field theory (MFT) within a two sub-lattice model. Study of the
magnetic phase diagram down to $T$ = 1.8 K reveals a change of magnetic
structure through a metamagnetic transition at around 20 kOe and the
disappearance of the AF ordering near 140 kOe. In total, our work indicates
that, GdPtPb can serve as an example of a planar, non collinear, AF with a
distorted Kagomé magnetic sub-lattice.