ACTA

From Cuprate to Nickelate: Evolution of the Normal State Properties with Ni from La_1.85Sr_0.15CuO₄ to La_1.85Sr_0.15NiO₄

V.L. Bezusyy^a, A. Malinowski^a, R. Minikayev^a, W. Paszkowicz^a, P. Dziawa^a and R. Gorzelniak^b
^aInstitute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
^bInstitute of Low Temperature and Structure Research, PAS, Okólna 2, 50-422 Wrocław, Poland

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The influence of Ni doping on the normal-state pseudogap in La_1.85Sr_0.15CuO₄ is studied by dc magnetic susceptibility measurements, accompanied by X-ray powder diffraction analysis and resistivity measurements. The measurements are carried out on the polycrystalline La_1.85Sr_0.15Cu_1-yNi_yO₄ samples in the whole doping range from y=0.01 up to y=1. The temperature of pseudogap opening is found to decrease above y=0.05 and to vanish when y exceeds 0.07. At small Ni content, up to y=0.07, the magnetic moment induced by Ni is constant and equal to 0.7 μ_B per Ni, while for larger y it increases abruptly and reaches about 1.6 μ_B per Ni ion for y = 0.5. The dependence of the normal-state resistivity on temperature evolves smoothly from the metallic-like for small y, to the variable range hopping, described by the Mott law with the exponent 1/4, for samples with y>0.15.

DOI: 10.12693/APhysPolA.118.402
PACS numbers: 74.25.Ha, 74.72.-h, 74.72.Kf, 75.30.-m