Temperature and field dependence of the magnetic properties of Nd <InlineEquation ID="Equ1"> <EquationSource Format="TEX">$\mathsf{_{2-x}}$</EquationSource> </InlineEquation>Ce<InlineEquation ID="Equ2"> <EquationSource Format="TEX">$\mathsf{_{x}}$</EquationSource> </InlineEquation>CuO<InlineEquation ID="Equ3"> <EquationSource Format="TEX">$\mathsf{_4}$</EquationSource> </InlineEquation>

We have investigated the magnetic ordering of Nd<Subscript>2-x </Subscript>Ce<Subscript> x </Subscript>CuO<Subscript>4</Subscript> for x=0, 0.09, 0.13, 0.15 and 0.18 by neutron diffraction at low temperatures down to 33 mK and under magnetic field up to 5 tesla applied along [1,-1,0] crystallographic direction. At zero applied magnetic field Cu magnetic sublattice orders at <InlineEquation ID="Equ4"> <EquationSource Format="TEX">$T_{N} \approx 250$</EquationSource> </InlineEquation>, 210, 130 and 105 K for x=0, 0.09, 0.13, 0.15, respectively. No long range magnetic order of the Cu could be detected for x=0.18. The magnetic order of Nd was found in all samples, with a gradual increase of the polarized magnetic moment with decreasing temperature, saturating around 1 K. Hyperfine induced nuclear polarization of the Nd nuclear spin has been observed below about 400 mK for samples with x=0, 0.13, 0.15 and 0.18. Field variation of the intensities of the principal and superstructure reflections of Nd<Subscript>2-x </Subscript>Ce<Subscript> x </Subscript>CuO<Subscript>4</Subscript> at millikelvin temperatures shows a field-induced second-order double-<Emphasis Type="Bold">k to single-<Emphasis Type="Bold">k phase transition at H <Subscript> c </Subscript>=0.75 and 0.56 tesla for samples with x=0 and 0.15, respectively at T=50 mK. We have also investigated the polarization of the Nd electronic sublattice due to the field of the Cu sublattice by the element specific X-ray resonant magnetic scattering investigation with synchrotron radiation. Copyright Springer-Verlag Berlin/Heidelberg 2004