2017/08/14 by Shukai Yu, C. Dhanasekhar, Venimadhav Adyam +13 · 13 citations
Materials Science · Physics and Astronomy · #Absorption (acoustics) #Condensed matter physics #Dielectric #Doping #Ferrimagnetism #Magnetic and transport properties of perovskites and related materials #Magnetic field #Magnetization #Materials science #Multiferroics and related materials #Optics #Optoelectronics #Phonon #Physics #Physics of Superconductivity and Magnetism #Refractive index #Terahertz radiation #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.96.094421
published in Physical review. B./Physical review. B 96(9) (American Physical Society)
openalex created_date 2017/07/14 · arxiv created 2017/08/14 · openalex publication_date 2017/09/19 · arxiv updated 2017/12/15 · openalex updated_date 2026/08/06
We present a study of the terahertz-frequency magnetoelectric effect in ferrimagnetic pyroelectric CaBaCo4O7 and its Ni-doped variants. The terahertz absorption spectrum of these materials consists of spin excitations and low-frequency infrared-active phonons. We studied the magnetic-field-induced changes in the terahertz refractive index and absorption in magnetic fields up to 17 T. We find that the magnetic field modulates the strength of infrared-active optical phonons near 1.2 and 1.6 THz. We use the Lorentz model of the dielectric function to analyze the measured magnetic-field dependence of the refractive index and absorption. We propose that most of the magnetoelectric effect is contributed by the optical phonons near 1.6 THz and higher frequency resonances. Our experimental results can be used to construct and validate more detailed theoretical descriptions of magnetoelectricity in CaBaCo_4\ensuremath-xNixO7.