Structural, Spectroscopic, and Magnetic Studies on Copper Tartrate Crystals

Copper tartrate crystals were grown by the gel growth method and characterised by energy-dispersive X-ray (EDAX), scanning electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy, Fourier transform infrared, photo-luminescence (PL), electron paramagnetic resonance, and low-temperature magnetic studies in the temperature range 300-20 K. The XRD study confirmed the orthorhombic structure of the crystal and the XPS study established the Cu2+ ions in the crystal. UV-vis study deduced the energy gap as 2.15 eV, confirming the semi-conducting nature, and Urbach energy as 0.4686 eV. PL showed the presence of Cu2+ vacancy-related defects. Low-temperature magnetic study confirmed the paramagnetic nature in the temperature range 300-77 K, and the crystal showed a weak ferromagnetic signal at 20 K, which is interesting. The magnetic field along with the low temperature caused an ordered spin orientation.