TY - JOUR
T1 - Magnetic polarons and the metal-semiconductor transitions in (formula presented) and EuO
T2 - Raman scattering studies
AU - Snow, C. S.
AU - Cooper, S. L.
AU - Young, D. P.
AU - Fisk, Z.
AU - Comment, Arnaud
AU - Ansermet, Jean Philippe
PY - 2001
Y1 - 2001
N2 - We present inelastic light scattering measurements of EuO and (formula presented) (formula presented) 0.005, 0.01, 0.03, and 0.05) as functions of doping, B isotope, magnetic field, and temperature. Our results reveal a variety of distinct regimes as a function of decreasing T: (a) a paramagnetic semimetal regime, which is characterized by a collision-dominated electronic scattering response whose scattering rate (formula presented) decreases with decreasing temperature; (b) a spin-disorder scattering regime, which is characterized by a collision-dominated electronic scattering response whose scattering rate (formula presented) scales with the magnetic susceptibility; (c) a magnetic polaron regime, in which the development of an (formula presented) spin-flip Raman response betrays the formation of magnetic polarons in a narrow temperature range above the Curie temperature (formula presented) and (d) a ferromagnetic metal regime, characterized by a flat electronic continuum response typical of other strongly correlated metals. By exploring the behavior of the Raman responses in these various regimes in response to changing external parameters, we are able to investigate the evolution of charge and spin degrees of freedom through various transitions in these materials.
AB - We present inelastic light scattering measurements of EuO and (formula presented) (formula presented) 0.005, 0.01, 0.03, and 0.05) as functions of doping, B isotope, magnetic field, and temperature. Our results reveal a variety of distinct regimes as a function of decreasing T: (a) a paramagnetic semimetal regime, which is characterized by a collision-dominated electronic scattering response whose scattering rate (formula presented) decreases with decreasing temperature; (b) a spin-disorder scattering regime, which is characterized by a collision-dominated electronic scattering response whose scattering rate (formula presented) scales with the magnetic susceptibility; (c) a magnetic polaron regime, in which the development of an (formula presented) spin-flip Raman response betrays the formation of magnetic polarons in a narrow temperature range above the Curie temperature (formula presented) and (d) a ferromagnetic metal regime, characterized by a flat electronic continuum response typical of other strongly correlated metals. By exploring the behavior of the Raman responses in these various regimes in response to changing external parameters, we are able to investigate the evolution of charge and spin degrees of freedom through various transitions in these materials.
UR - http://www.scopus.com/inward/record.url?scp=84865193233&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84865193233&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.64.174412
DO - 10.1103/PhysRevB.64.174412
M3 - Article
AN - SCOPUS:84865193233
SN - 1098-0121
VL - 64
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 17
ER -