PAC-experiments in electron-doped HTSC: Nd2?x CexCuO4

The perturbed angular correlation (PAC) method was applied to study the electron-doped HTSC Nd_2–x Ce_xCuO₄ (NC_xCO) forx=0, 0.06, 0.1 and 0.15.¹¹¹In was implanted at 400 keV into sintered bulk samples. After annealing the radiation damage at 1223 K in air, PAC spectra were taken at measuring temperatures between 15 and 823 K. Point charge model (pcm) calculations support the assumption that¹¹¹In replaces a Nd-ion. The width of the main frequency depends on the amountx of Ce-doping. The magnitude of the observed electric field gradient (efg) can be explained if the¹¹¹In probe catches simultaneously an oxygen vacancy at the O(2)-site.This work was supported by the BMFT, FKZ 13 N54930.