Softening and Broadening of the Zone Boundary Magnons in <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>Pr</mi></mrow><mrow><mn>0.63</mn></mrow></msub></mrow><mrow><msub><mrow><mi>Sr</mi></mrow><mrow><mn>0.37</mn></mrow></msub></mrow><mrow><msub><mrow><mi>MnO</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math></span>

H. Y. Hwang; P. Dai; S-W. Cheong; G. Aeppli; D. A. Tennant; H. A. Mook

doi:10.1103/PhysRevLett.80.1316

Softening and Broadening of the Zone Boundary Magnons in $\Pr_{0.63} {Sr}_{0.37} {MnO}_{3}$

H. Y. Hwang, P. Dai, S-W. Cheong, G. Aeppli, D. A. Tennant, and H. A. Mook

Phys. Rev. Lett. 80, 1316 – Published 9 February 1998

Abstract

We have studied the spin dynamics in $\Pr_{0.63} {Sr}_{0.37} {MnO}_{3}$ above and below the Curie temperature $T_{C} = 301$ K. Three distinct new features have been observed: a softening of the magnon dispersion at the zone boundary for $T < T_{C}$ , significant broadening of the zone boundary magnons as $T \to T_{C}$ , and no evidence for residual spin-wave-like excitations just above $T_{C}$ . The results are inconsistent with double exchange models that have been successfully applied to higher $T_{C}$ samples, indicating an evolution of the spin system with decreasing $T_{C}$ .

Received 14 March 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.1316

Authors & Affiliations

H. Y. Hwang¹, P. Dai², S-W. Cheong¹, G. Aeppli³, D. A. Tennant², and H. A. Mook²

¹Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974
²Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
³NEC Research Institute, 4 Independence Way, Princeton, New Jersey 08540