We developed an experimental method for measuring the intrinsic susceptibility \chi of powder of cuprate superconductors in the zero field limit using a DC-magnetometer. The method is tested with lead spheres. Using this method we determine \chi for a number of cuprate families as a function of doping. A universal linear (and not proportionality) relation between Tc and \chi is found. We suggest possible explanations for this phenomenon.
@article{arxiv.cond-mat/0504293,
title = {Universal linear relations between susceptibility and Tc in cuprates},
author = {Amit Kanigel and Amit Keren and Arkady Knizhnik and Oren Shafir},
journal= {arXiv preprint arXiv:cond-mat/0504293},
year = {2009}
}