2 research outputs found
Possible high temperature superconducting transitions in disordered graphite obtained from room temperature deintercalated KC
Although progress with twisted graphene nano-devices is boosting the
superconductivity that is the consequence of their Moir\'e flat electronic
bands, the immense choice for future development is an obstacle for their
optimisation. We report here that soft-chemistry deintercalation of KC
breaks down graphite stacking generating a strong disorder that includes
stacking twists and variable local doping. We obtain a bulk graphite whose
individual crystallites have different stackings with arbitrary twists and
doping, scanning in the same sample a huge number of stacking configurations.
We perform magnetisation measurements on batches with different synthesis
conditions. The disorder weakens the huge diamagnetism of graphite, revealing
several phase transitions. A "ferromagnetic-like" magnetisation appears with
Curie temperatures T450K, that has to be subtracted from the measured
magnetisation. Depending on sample synthesis, anomalies towards diamagnetic
states appear at T110K (3 samples), 240K (4 samples),
320K (2 samples). Electrical resistivity measurements yield anomalies for
the T240K transition, with one sample showing a 90% drop. We discuss
the possibility that these (diamagnetic and resistitive) anomalies could be due
to superconductivity.Comment: 15 pages, 10 figure