The non-centrosymmetric heavy fermion compound CePt 3 Si orders antiferromag-netically at T N = 2.2K, followed by a superconducting transition, where T s = 0.45 K for high quality samples and T s = 0.75K for lower quality samples. We have used neutron Larmor diffraction to measure the temperature dependence and distribution of the lattice constants in a single crystal of CePt 3 Si with T s = 0.75K. In our study we observe an unusually wide range of lattice parameters for the a-axis and c-axis with $\Delta$ a/a $\approx$ $\Delta$ c/c $\approx$ 10 -3 . Small angle neutron scattering suggests an abundance of defects along the lattice planes. When taking into account the pressure dependence of T s our study attributes the increased value of T s in low quality samples to an effective negative pressure.     «

The non-centrosymmetric heavy fermion compound CePt 3 Si orders antiferromag-netically at T N = 2.2K, followed by a superconducting transition, where T s = 0.45 K for high quality samples and T s = 0.75K for lower quality samples. We have used neutron Larmor diffraction to measure the temperature dependence and distribution of the lattice constants in a single crystal of CePt 3 Si with T s = 0.75K. In our study we observe an unusually wide range of lattice parameters for the a-axis and c-axis wi...     »