Paramagnetic resonance in La2NiMnO6 probed by impedance and lock-in detection techniques

• Published in: arXiv.org
• Main Authors: Chaudhuri, Ushnish, Debendra Prasad Panda, Sundaresan, A, Mahendiran, R
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 17.05.2020
• Subjects: Broadband; Coils; Coils (strip); Coplanar waveguides; Damping; Frequency analysis; Frequency ranges; Impedance method; Line shape; Magnetic fields; Magnetic permeability; Paramagnetic resonance; Perovskites; Physics - Materials Science; Reactance; Room temperature; Spin-orbit interactions; Strip
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2005.08142

We report the detection of paramagnetic resonance in the double perovskite La2NiMnO6 at room temperature for microwave magnetic fields with frequencies, f = 1 GHz to 5 GHz, using two cavity-less methods. We use an indirect impedance method which makes use of a radio frequency impedance analyzer and a folded copper strip coil for the frequency range f = 1 to 2.2 GHz. In this method, when an applied dc magnetic field is swept, high-frequency resistance of the strip coil exhibits a sharp peak and the reactance curve crosses zero exhibiting resonance. A lock-in based broadband setup using a coplanar waveguide for microwave excitation was used for f = 2 to 5 GHz The resonance fields (Hr) obtained from both the techniques increase linearly with frequency and a large spectroscopic g-factor, equal to 2.1284, which supports the presence of Ni2+ cation with strong spin-orbit coupling. Line shape analysis and analytical fitting were performed to characterize the material in terms of its initial susceptibility and damping parameters.