The effect of hole-doping on the magnetic properties of Nd1-xTiO3

Abstract

The magnetic properties of the hole(x)-doped Mott-Hubbard, antiferromagnetic insulator, NdTiO3, have been investigated in Nd1-xTiO3. For the materials in 0.010(6) < x < 0.112(4), correlation between the structural and magnetic properties is discussed with respect to the Ti - O - Ti angles and the Ti - O bond distances. For 0.010(6) < x < 0.071(10), long-range magnetic order is observed through low temperature neutron diffraction and heat capacity. Neel ordering temperatures of 88.2 K and 61.9 K are determined, respectively, for x = 0.019(6) and x = 0.064(10). From high resolution neutron diffraction, the Pnma magnetic structure is assigned, unambiguously, as GxCy on Ti3+ and Cy2 on Nd3+. The Ti3+ ordered moment decreases gradually from 0.45(8) uB for x = 0.019(6) to 0.31(7) uB for x = 0.071(10), but vanishes abruptly for higher x. Antiferromagnetic short-range order exists for 0.074(9) < x < 0.098(10) as determined by neutron diffraction and the field-dependence of the susceptibility. This is the first observation of short-range order for any hole-doped titanate system. For 29(4)% hole-doping in Nd1-xTiO3, x > 0.098(10), all magnetic ordering is destroyed.