Spectacular Doping Dependence of Interlayer Exchange and Other Results on Spin Waves in Bilayer Manganites
Spectacular Doping Dependence of Interlayer Exchange and Other Results on Spin Waves in Bilayer Manganites
We report the measurement of spin waves in the bilayer colossal magnetoresistive manganites La2-2xSr1+2xMn2O7 with x = 0.30, 0.35, and 0.40. For x = 0.35 and 0.40 the entire acoustic and optic dispersion relations are well described by those for a bilayer Heisenberg Hamiltonian with nearest-neighbor exchange only, which is …