Detection of Spin Canting Using Magnetic Field Modulated Microwave Spectroscopy.*

Magnetic field modulated microwave spectroscopy (MFMMS) is the most sensitive technique for detecting superconducting transitions[1]. While superconducting transitions exhibit a reproducible peak behavior, magnetic transitions can have a range of responses including: slopes, steps and local minima in the temperature dependent MFMMS measurements. Other work has shown that a magnetic response in a similar microwave spectroscopy technique can be caused by spin canting[2]. One system of materials that provides an interesting test case for this is the Ruthenocuprates[3]. These compounds have a ferromagnetic response due to spin canting, above the onset of superconductivity. Here, we show that the temperature and field dependence of spin canting of the Ru-1212 system (RuSr₂GdCu₂O₈) can be determined by comparing the MFMMS to magnetometry and resistance measurements.

1. J.G. Ramírez, A.C. Basaran, J. de la Venta, J. Pereiro, and I.K. Schuller, Rep. Prog. Phys. 77, 093902 (2014).
2. G. Alvarez, H. Montiel, J.F. Barron, M.P. Gutierrez, and R. Zamorano, J. Magn. Magn. Mater. 322, 348 (2010).
3. W. Klamut, Supercond. Sci. Technol. 21, (2008).