Tuning Magnetic Properties of a Carbon Nanotube-Lanthanide Hybrid Molecular Complex through Controlled Functionalization

Abstract

Molecular magnets attached to carbon nanotubes (CNT) are being studied as potential candidates for developing spintronic and quantum technologies. However, the functionalization routes used to develop these hybrid systems can drastically affect their respective physiochemical properties. Due to the complexity of this systems, little work has been directed at establishing the correlation between the degree of functionalization and the magnetic character. Here, we demonstrate the chemical functionalization degree associated with molecular magnet loading can be utilized for controlled tuning the magnetic properties of a CNT-lanthanide hybrid complex. CNT functionalization degree was evaluated by interpreting minor Raman phonon modes in relation to the controlled reaction conditions. These findings were exploited in attaching a rare-earth-based molecular magnet (Gd-DTPA) to the CNTs. Inductively coupled plasma mass spectrometry, time-of-flight secondary ion mass spectrometry and super conducting quantum interference device (SQUID) measurements were used to elucidate the variation of magnetic character across the samples. This controlled Gd-DTPA loading on the CNT surface has led to a significant change in the nanotube intrinsic diamagnetism, showing antiferromagnetic coupling with increase in the Weiss temperature with respect to increased loading. This indicates that synthesis of a highly correlated spin system for developing novel spintronic technologies can be realized through a carbon-based hybrid material.

Observation of High Magnetic Bistability in Lanthanide (Ln = Gd, Tb and Dy)-Grafted Carbon Nanotube Hybrid Molecular System

“…Furthermore, spin valve devices made out of this hybrid material have shown giant magnetoresistance at low temperatures [26]. In 2018, we reported the Kondo effect with enhanced magnetic properties in a Gd-MWCNT system [25], and thereafter demonstrated how the magnetic properties could be tuned by the careful chemical functionalization of MWCNTs [32]. Later, we showed how spin relax through interaction (spin-phonon coupling) with the discrete phonon spectrum of CNTs [33].…”

“…It is envisaged that the non-covalent attachment of the molecules preserves the integrity and electronic character of the carbon nanotubes. There are, however, studies reporting the successful covalent attachment of molecules to CNTs without hindering the electronic properties of the CNTs [39] through a careful degree of acid treatment during CNT functionalization [32]. Furthermore, it is interesting to study the surface interactions between CNTs and metal ions stabilized with EDTA ligand.…”

Effect of functionalized multiwalled carbon nanotubes on the mechanical, swelling and viscoelastic properties of gum ghatti-cl-poly(NIPAm) hydrogels

“…8 Since the discovery of carbon nanotubes (CNTs) in 1991, the study of these structures has been of great interest. 9 This is owing to the wide range of properties displayed by CNTs (and other composite materials modified using this nanostructure), such as their outstanding mechanical strength with low density 10 and electrical, 11 magnetic, 12 and catalyst carrying 13 properties. Carbon nanotubes (CNTs) have attracted interest from many researchers due to their unique structural, electrical, and mechanical properties, which make them versatile in a variety of fields.…”

Improved Mechanical, Anti-UV Irradiation, and Imparted Luminescence Properties of Cyanate Ester Resin/Unzipped Multiwalled Carbon Nanotubes/Europium Nanocomposites

“…However, pure lanthanide complexes and polymer matrix have unstable luminescence properties. Therefore, we first attached the lanthanide compound on the side wall of carbon nanotubes to prepare luminescence carbon nanotubes [ 32 , 33 ]. For example, Wu et al coated the multiwalled carbon nanotubes by lanthanide (Eu 3+ , Tb 3+ ) complexes and obtained luminescence materials with excellent luminescence stability through a simple in situ synthesis method [ 34 ].…”