Effects of Cu-doping on the vibrational and electronic properties of epitaxial PrNiO3 thin films

EXAFS evidence for the spin–phonon coupling in the monoclinic PrNiO3 nickelate perovskite

“…See DOI: 10.1039/x0xx00000x sized rare-earths (R = Nd-Er, and Nd0.7La0. 3) falls in between the one of LaNiO3 and YNiO3. These medium-size R cation nickelates also exhibit the antiferromagnetic ordering state at low temperature.…”

“…1 The origin and systematics of this transition remains, however, highly debated despite of its importance for fine-tuning their properties for industrial applications. [2][3][4][5] While there is a general consensus that the bandgap closure mechanism involves orbital overlapping between adjacent Ni and O ions, the involvement of the R cation orbitals remains less constrained. 6,7 Detailed information on the structural and concomitant electronic changes occurring during this transition is required, but is presently only available for a restricted amount of R cations.…”

X-ray absorption near-edge, terahertz and Raman spectroscopies evidence growth-orientation dependent cation order, phase transitions and spin–phonon coupling in half-metallic Ca2FeMoO6 thin films

“…In the metallic state, the resistivity as a function of temperature can be described as [24,25]: where ρ 0 is residual resistivity which is a temperature-independent term, existing due to lattice imperfections, impurities, grain boundary contributions, etc, ρ n governs the strength of electron-electron interactions, and n is an adjustable parameter. According to the classical Fermi liquid model, the value of exponent n remains 2, which explains the quadratic dependence of resistivity over temperature [21].…”

“…The temperature-induced thermal expansion of the lattice produces red-shift of the Raman modes as expected. For a magnetic material, the red-shift of Raman modes can be attributed to various factors such as [24,32,33]: ω (T) = ω 0 + ∆ω ph−ph + ∆ω sp−ph + ∆ω anharmonic (7) where ω 0 is the Raman shift corresponding to 0 K, ∆ω ph-ph is the cell volume contribution, ∆ω sp-ph is the spin-phonon coupling contribution and ∆ω anharmonic signifies the contribution of anharmonic terms in the system. Here, ∆ω sp-ph arises because of modulation of spin exchange integral by a change in the lattice vibrational frequencies and hence signifies contribution from spin-phonon interactions.…”

Process-Gas-Influenced Anti-Site Disorder and Its Effects on Magnetic and Electronic Properties of Half-Metallic Sr2FeMoO6 Thin Films

“…Micro-Raman spectroscopy gives insightful details about local structure, phase purity, and electron-phonon interactions in a material [25,26]. It can be noted that Raman spectroscopy of SFMO is less explored regardless of the extensive research carried out on this system.…”