88th Annual Meeting of the Southeastern Section of the APS
Volume 66, Number 16
Thursday–Saturday, November 18–20, 2021;
University Center Club, Florida State University, Tallahassee, Florida
Session K02: Condensed Matter II
11:00 AM–12:30 PM,
Friday, November 19, 2021
Room: West Ballroom
Chair: Kaya Wei, NHMFL
Abstract: K02.00001 : Probing spin-phonon coupling in magnetic materials using magneto-Raman spectroscopy*
11:00 AM–11:30 AM
Preview Abstract
Abstract
Author:
Komalavalli Thirunavukkuarasu
(Florida A&M University)
Combining spectroscopy with one or more external parameters such as low
temperature, high pressure, and high magnetic fields, allows us to
continuously tune correlations to probe properties of materials across their
phase diagram. Recently, we employed magneto-Raman spectroscopy on two
different kinds of magnetic materials. The first compound is
SrCu$_{2}$(BO$_{3})_{2}$. It is a quasi-2D orthogonal spin dimer system
with a spin singlet ground state and is a typical example for the
Shastry-Sutherland model. It exhibits a sequence of magnetization plateau at
magnetic fields higher than 20 T. The unique behavior results from interplay
between geometrical frustration and quantum fluctuations. I will discuss the
origin of the strong spin-lattice coupling in SrCu$_{2}$(BO$_{3})_{2}$
revealed by Raman studies at high magnetic fields up to 45T. The second
compound is the multiferroic metal organic framework
[(CH$_{3})_{2}$NH$_{2}$]Co(HCOO)$_{3}$ belonging to the family of MOFs
comprised of methylammonium (A$=$ (CH$_{3})_{2}$NH$_{2})$ and metal
(B$=$Co, Cu, Fe, Mn, Ni) cations with a formate (X$=$HCOO$_{3})$ anion.
Several efforts have been made to understand the exchange interactions in
these functional materials including magnetization at high magnetic fields
up to 60 T and infrared spectroscopy at magnetic fields up to 35 T. In the
infrared studies under applied magnetic fields, it was concluded that Co
complex adopts a different mechanism for facilitating saturation of magnetic
states by involving formate stretching distortions unlike other complexes in
the family that use the formate bending mode. In this talk, I will discuss
our Raman spectroscopy on [(CH$_{3})_{2}$NH$_{2}$]Co(HCOO)$_{3}$ at
magnetic fields up to 31T to probe the magneto-elastic coupling.
This work has been performed at the user facilities in the National High
Magnetic Field Laboratory (NHMFL), Tallahassee. The NHMFL is supported by
the National Science Foundation through NSF/DMR-1644779 and the state of
Florida. The project is also funded by DoN HBCU/MI program award {\#}
N000141713061.
*Probing spin-phonon coupling in magnetic materials using magneto-Raman spectroscopy