Neutron Scattering Investigation of Magnetic Bilayer Correlations in La1.2Sr1.8Mn2O7 : Evidence of Canting above TC

Neutron scattering investigations of the paramagnetic correlations in the layered manganite La1.2Sr 1.8Mn2O7 , which exhibits colossal magnetoresistance above the Curie transition at TC=112 K , show that spins in neighboring layers within each bilayer are strongly canted at an average angle that is dependent on both the magnetic field and the temperature, as predicted by de Gennes. The in-plane correlation length does not diverge at TC , although the magnetic Bragg intensity obeys critical scaling below TC , with the same temperature dependence as the zero-field electrical conductance. copyright 1998 The American Physical Society