Chapter 21 Effect of Magnetic Ordering on Phonon Raman Spectra in Magnetic Systems Jeel Swami, Ambesh Dixit and Brajesh Tiwari Abstract We present a short review on phonon anomalies near magnetic ordering in magnetic materials using the noticed Raman shifts and any change in intensities near such magnetic ordering. The observed variation in specific optical phonon modes is discussed considering the spin-orbital-phonon coupling in various systems. The consequences of spin-orbital-phonon coupling include the impact on bond strength, which results in specific phonon mode anomalies near magnetic ordering. There are several experimental observations based on temperature-dependent Raman and IR spectroscopic measurements in the vicinity of magnetic ordering temperature, suggesting a crucial spin-phonon coupling in certain materials, giving rise to the exotic physical properties such as magnetoelectric, and piezomagnetic effects in such materials. The review will discuss the microscopic origin of spin-orbital-phonon coupling in these systems. 21.1 Introduction Vibrational spectroscopy is a sensitive tool to probe the interplay among lattice, spin, charge and orbital degrees of freedoms in materials [1–5]. Exotic behavior in metal oxides are the manifestation of delicate interplay and cross-coupling among lattice, spin, orbital and charge degrees of freedom such as colossal magnetoresistance, multiferroics, and magnetoelectric coupling, high-T c superconductors, etc. These complex phenomena motivate for a closer look in the complex interplay among these degrees of freedom in different material systems. There are several reports present in literature, discussing the microscopic origin of exotic properties in these J. Swami · B. Tiwari (B ) Department of Physics, Institute of Infrastructure, Technology, Research and Management, Ahmedabad 380026, Gujarat, India e-mail: brajeshtiwari@iitram.ac.in A. Dixit Department of Physics and Centre for Energy, Indian Institute of Technology Jodhpur, Rajasthan 342011, India © Springer Nature Singapore Pte Ltd. 2019 D. K. Singh et al. (eds.), Advances in Spectroscopy: Molecules to Materials, Springer Proceedings in Physics 236, https://doi.org/10.1007/978-981-15-0202-6_21 289