Structural, transport, and magnetic properties of Nd1-xCaxMnO3 have been studied to probe the consequence of strong lattice distortion and reduced double exchange. Charge ordering has been observed over a large composition range of 0.30≤x≤0.80. For 0.33≤x≤0.40, at low temperatures, a magnetic field induces a first-order antiferromagnetic semiconductor to ferromagnetic metal transition and reduces the resistance by several orders of magnitude. These results illustrate the competition between doub…
Read moreStructural, transport, and magnetic properties of Nd1-xCaxMnO3 have been studied to probe the consequence of strong lattice distortion and reduced double exchange. Charge ordering has been observed over a large composition range of 0.30≤x≤0.80. For 0.33≤x≤0.40, at low temperatures, a magnetic field induces a first-order antiferromagnetic semiconductor to ferromagnetic metal transition and reduces the resistance by several orders of magnitude. These results illustrate the competition between double exchange and mechanisms that promote charge localization.