Defect-induced measurements of semi-organic ammonium hydrogen oxalate oxalic acid dihydrate single crystals using gamma irradiation

Abstract

The structural, optical, mechanical and electrical properties of pure and 5—20-kGy gamma-irradiated semi-organic single crystals of ammonium hydrogen oxalate oxalic acid dihydrate (NH₄H₃(C₄O₈).2H₂O) are presented. The crystals were synthesized at room temperature using facile solvent evaporation technique. Powder XRD measurements indicate gradual enhancement in crystallinity and lattice defect annihilation for low radiation dosage. Radiation-induced increase in optical band gap (4.01–4.16 eV) indicates high damage threshold of the crystals. Quenching of photoluminescence is attributed to the lowering of surface defect density with radiation. The influence of gamma radiation on the functional vibrations of the crystals is studied using FTIR-Raman spectroscopy. Vickers microhardness measurements show gradual enhancement in crystal hardness with the increase in radiation. An increase in forward resistance with irradiation is observed from I–V measurements and is attributed to high transparency of the crystals. These results indicate the viability of NH₄H₃(C₄O₈) 2H₂O crystals in potential space optoelectronic applications.

KEYWORDS:

• Ammonium hydrogen oxalate oxalic acid dihydrate
• gamma radiation
• defect annihilation
• space optoelectronic applications

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

K. Mahendra

Dr. K. Mahendra, obtained his Ph.D in Physics in 2020 from National Institute of Technology Karnataka, Surathkal, India. His research interests include crystal growth, photocatalysis, oxide materials etc,. He has authored several publications in peer-reviewed international journals and presented papers in international conferences.

Jean Maria Fernandes

Dr. Jean Maria Fernandes obtained her Ph.D. in Physics in 2018 from National Institute of Technology Karnataka, Surathkal, India. Her research interests include organic electronics, semi-organic crystals, perovskites, transparent conducting electrodes for optoelectronic applications. She has authored several publications in peer reviewed international journals and presented papers in international conferences.

N. K. Udayashankar

Dr. N. K. Udayashankar, working as Professor at National Institute of Technology Karnataka, Surathkal, India. His research interests includes Anodization, Material Characterization, Electrodeposition, Nanomaterials, Nanostructured Materials. He has authored several publications in peer-reviewed international journals and presented papers in international conferences.