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arXiv · 1906.01281

Observation of spin-phonon coupling in GdCl3 filled carbon nanotubes

S. Ncube·R. Erasmus·S. Bhattacharyya
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Abstract

The enhancement of spin-phonon coupling in gadolinium filled double walled carbon nanotubes (GdCl3@DWNTs) is demonstrated through temperature dependent magnetrometry and polarized Raman Spectroscopy (PRS). Temperature dependent susceptibility measurements show that the GdCl3@DWNTs undergo a superparamagnetic phase transion at temperatures below 100 K with a blocking temperature at approximately 47 K. From the temperature dependent PRS, it is observed that a distinct phonon hardening occurs for the G-band modes at temperatures close to the onset of the superparamagentic phase. This is in contract to pristine DWNTs where phonon modes saturates to a constant frequency at low temperatures. The abrupt increase in phonon frequency is indicative of a pronounced spin-phonon coupling. The enhanced coupling in the GdCl3@DWNTs is believed to occur due to resonance between nanotube phonon mode and spin flip frequency as temperature decreases.

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S. Ncube, R. Erasmus, S. Bhattacharyya. 2019-06-04. Observation of spin-phonon coupling in GdCl3 filled carbon nanotubes. https://arxiv.org/abs/1906.01281

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