Infrared Reflectivity of the Solid Solutions LaNi1-xFexO3; (0.00≤x≤1.00)

NÉSTOR E. MASSA; HORACIO FALCÓN; HORACIO SALVA; RAÚL E. CARBONIO

American Physical Society

Año: 1997 vol. 56 p. 10178 - 10178

p style="TEXT-ALIGN: justify; LINE-HEIGHT: 200%; MARGIN: 0cm 0cm 0pt" class="MsoNormal">We report temperature-dependent far- and midinfrared reflectivity spectra of LaNi(1-x)FexO3 (0.00≤x≤1.00) solid solutions that span the passage from LaFeO3, a room-temperature antiferromagnetic insulator, to LaNiO3, a known metal oxide. Light Ni doping creates defects that induce extra bands assigned to electronic transitions within the insulating gap. An incipient Drude term emerges in the reflectivity spectrum of LaNi0.39Fe0.61O3 together with subbands that contribute to the electronic background. At these concentrations the dielectric response shows a picture in which the spectral weigh switches over toward far-infrared frequencies while phonon features develop strong antiresonances near longitu