Effect of xylenol orange dye on morphological, optical, piezo-/di-electric and mechanical properties of potassium hydrogen phthalate single crystals. (May 2020)

• Record Type: Journal Article
• Authors: Kumar, Sandeep; Sinha, Nidhi; Goel, Sahil; Kumar, Binay
• Is Part Of: Vacuum. Volume 175(2020)
• Publication Date: 2020-05
• Subjects: Dye doped KAP -- Powder X-ray diffraction -- Optical properties -- Dielectric properties -- Micro-indentation; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2020.109240
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: Pure and xylenol orange (XO; C 13 H 32 N 2 O 13 S ;0.1 mol%) dye doped potassium hydrogen phthalate (KAP; C 8 H 5 KO 4 ) crystal were grown by solution technique. Only {11 1 ‾ } & {110} growth sectors of KAP crystal got selectively stained by the XO dye molecules with {010} being the largest visible (morphologically important) plane. Powder XRD pattern reveals that XO dyeing did not resulted in any extra Bragg peaks and hence, didn't changed the basic structure of KAP crystal (PCa21 ). HRXRD and etch pit density studies were performed to investigate the effect of XO dye staining on the crystallinity of KAP crystal.The Piezoelectric charge coefficient increased (1.42–1.62 pC/N), optical transparency increased (30%–50%), mechanical strength improved (10.2–11 kg/mm 2 @ 20 g), dielectric constant enhanced ( ε ' ~40 to 44 @ 1 kHz) and dielectric loss decreased (~0.09 to ~0.02) due to XO dye doping. Comparative optical, mechanical, piezoelectric and dielectric investigations add to the scientific insights of KAP crystals and suggest XO-dyed KAP crystal as a better alternative than pure KAP crystal for opto-electronic devices applications. Graphical abstract: Image 1 Highlights: Pure and XO dyed KAP crystals were grown by slow evaporation solution technique. Inclusion of XO-dye in selective KAP-planes was confirmed under UV illumination. Optical band gap tuning and PL shifting were observed by XO-doping. Enhancement of mechanical strength by XO doping observed in micro-indentation studies. XO-staining found to improve -dielectric behaviour of KAP.