Vol.:(0123456789) 1 3 Journal of Materials Science: Materials in Electronics https://doi.org/10.1007/s10854-018-9888-0 Gamma irradiation efect on structural, optical and electrical properties of organometallic potassium hydrogen oxalate oxalic acid dihydrate single crystal K. Mahendra 1  · Kavya K. Nayak 1  · Brian Jeevan Fernandes 1  · N. K. Udayashankar 1 Received: 5 February 2018 / Accepted: 16 August 2018 © Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract Potassium oxalate oxalic acid dihydrate (KHO) single crystals were grown from solvent evaporation technique at room temperature. Crystals were optically characterized using UV–Vis and photoluminescence analysis. The gamma irradiation efects on KHO crystals were also studied optically and the results were analyzed to compare the efect of irradiation on the crystal lattice for diferent dosage. Structural variations were studied using powder XRD, FTIR and the results were examined to study the defect states created inside the lattice due to irradiation and the efect on the functional vibrations of the host crystal. Surface morphology of the crystal was studied using scanning electron microscope (SEM). Photo conductivity of the synthesized crystals were studied and analyzed to compare the photo response as well as the conductivity of the materi- als when subjected to irradiation. 1 Introduction In recent years the optoelectronic materials are gain- ing importance because of their potential applications in space, such as light detecting systems, orbital space mis- sions and space based ranging systems [1, 2]. Metalorganic single crystals are one such important materials owing to their potential applications in the feld of optoelectronics [3]. Although organic materials possess good optical prop- erties, they have low mechanical and thermal stabilities [4–6], whereas inorganic materials possess higher mechani- cal strength and can sustain more heat [7]. It is also highly challenging to grow large size organic crystals when com- pared to inorganic crystals. However, inorganic materials lack optical properties and chemical fexibility. This has led to the search and development of a new class of mate- rials which combines the advantages of both organic and inorganic materials, and overcomes their drawbacks. This class of materials has a metal atom in combination with organic molecules in its structure. In space applications, optoelectronic materials need to withstand the presence of high-energy photons (> 30 MeV) (space radiations). These high energy radiations can ionize the atoms and change the structural properties of the material, thereby damaging it [8]. Understanding the efects of high energy radiations is important in order to study their suitability in space applica- tions. The heavy ions and gamma irradiation on crystalline materials change the physical, optical, and electrical prop- erties of these materials [9–11]. In space communication systems the devices used are designed to work under the presence of external felds of strong ionizing radiations. It is required to know whether the used devices sustain the exposure of external high and low energy radiations [12, 13]. The high-energy radiations such as protons, gamma & heavy ions can cause damage in materials. If the energy of the incident photons having greater than the binding energy of the system then the atom can be knocked out from its lattice site and leads to the formation of color centres and defect formations [14]. Such defect formations will afect its optical and electrical properties of the material [8, 15]. In the present work, single crystals of triclinic organome- tallic KHO were grown using slow evaporation technique at room temperature. The grown crystals were irradiated using Co-60 gamma radiation in total dose ranging from 5 to 20 kGy. For the frst time, we report the efect of gamma irradiation on the optical, structural and electrical proper- ties of the grown KHO single crystals. Furthermore, we * K. Mahendra mahendra.ph13f06@nitk.edu.in 1 Department of Physics, National Institute of Technology Karnataka, P.O. Shrinivasnagar, Surathkal, Karnataka 575025, India