Ferromagnetic resonance study of Pr0.5(Ca1−xSrx)0.5MnO3

✍ Scribed by E. Winkler; M.T. Causa; C.A. Ramos

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 227 KB
• Volume: 398
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2007.04.084

✦ Synopsis

We study the competing phases at the crossover from localized to itinerant electronic behavior in the system Pr 0.5 (Ca 1Àx Sr x ) 0.5 MnO 3 , with 0.10pxp0.75. The study was performed by Q-band (35 GHz) electron spin resonance (ESR) spectroscopy. At room temperature, the samples show a single Lorentzian line centered at g ¼ 2.020 (5). Instead, at low temperature all the samples present a ferromagnetic resonance line (FMR) that coexists with a paramagnetic (PM) absorption. For x ¼ 0.15, the FMR absorption is observed at T C ¼ 200 K. This transition shifts to higher temperatures when x increases and for x ¼ 0.75, T C ¼ 260 K. The ferromagnetic metallic (FM) phase changes from a minority phase, when xo0.2, to a majority one, for x40.2. We fit the temperature dependence of the ESR spectra considering an FM phase with uniaxial anisotropy that coexists with a PM phase. We have found that the anisotropy field of the FM phase increases with x.