Growth, structure and spectral studies of a novel mixed crystal potassium zinc manganese sulphate J. Vijila Manonmoni a , G. Bhagavannarayana b , G. Ramasamy a , Subbiah Meenakshisundaram a M. Amutha a,⇑ a Department of Chemistry, Annamalai University, Annamalai Nagar 608002, India b Head, Materials and Characterization Division, N.P.L., K.S. Krishna Road, New Delhi 110012, India highlights  Mixed crystal K 2 Zn 0.84 Mn 0.16 (SO 4 ) 2 6H 2 O belongs to monoclinic system with P21/c space group.  High-resolution XRD reveals the presence of vacancy type defects in the mixed crystal.  Co-existence of Zn and Mg in the mixed crystal is confirmed by single crystal XRD, EDS and AAS. graphical abstract article info Article history: Received 11 April 2013 Received in revised form 18 July 2013 Accepted 21 July 2013 Available online 7 August 2013 Keywords: Crystal structure HRXRD FT-IR spectroscopy Tutton salt abstract Mixed crystals of K 2 Zn 0.84 Mn 0.16 (SO 4 ) 2 6H 2 O were grown from an equimolar aqueous solution of Tutton’s salt, K 2 Zn(SO 4 ) 2 6H 2 O and MnSO 4 by slow evaporation solution growth technique. The crystal composi- tion as determined by single crystal XRD analysis reveals the co-existence of zinc and manganese in the mixed crystal. The surface morphological changes are observed by scanning electron microscopy. Small variations in cell parameter values, slight shifts in characteristic vibrational patterns in FT-IR and reduc- tion in intensities observed in XRD confirm the crystal stress as a result of formation of mixed crystal. High resolution XRD diffraction estimates the crystalline perfection of the mixed crystal with predomi- nantly vacancy type of defects. It belongs to P2 1 /c space group with cell parameter values, a = 6.1530 Å, b = 12.2230 Å, c = 9.0430 Å, a = b = m = 90°, V = 657.56 Å 3 , Z = 4. High transmittance in the visible region is observed. Ó 2013 Elsevier B.V. All rights reserved. Introduction Tutton’s salts are potential conductors due to the existence of comparatively strong hydrogen bonds. Zinc potassium sulphate hexahydrate K 2 Zn(SO 4 ) 2 6H 2 O belongs to a large number of iso- morphic compounds with a general formula Me 0 Me 00 (XO 4 ) 2 6H 2 O (Me 0 = K, NH þ 4 , Rb, CS; Me 00 = Mg, Mn, Co, Ni, Cu, Zn, X = (S, Se) [1,2]. It crystallizes in the monoclinic system with space group P2 1 /c [3]. Detailed studies on vibrational patterns of NH þ 4 and SO 2 4 ions in Tutton’s salts have been carried out [4–8]. EPR studies on Mn(II) –, Cu(II) – and VO(II) – doped single crystal of K 2 Zn(SO 4 ) 2 6H 2 O [9–11] and other Tutton’s salts [12–14] have been reported. The crystal chemistry, metal–water interaction and the system of hydrogen bonds in different series of the Tutton salts, Rb sulfates [15], Rb selenates [16] and Cs sulfates [17] by sin- gle crystal and powder diffraction have been discussed. Recently, we have reported the growth, structure and crystalline perfection of Zn 0.54 Mg 0.46 (NH 4 ) 2 SO 4 6H 2 O [18]. Although, extensive studies 1386-1425/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.saa.2013.07.089 ⇑ Corresponding author. Tel.: +91 4144 238278. E-mail addresses: orkayedn@gmail.com, aumats2009@gmail.com (M. Amutha). Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 117 (2014) 9–12 Contents lists available at ScienceDirect Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy journal homepage: www.elsevier.com/locate/saa