Chemistry and Materials Research www.iiste.org ISSN 2224- 3224 (Print) ISSN 2225- 0956 (Online) Vol.9 No.2, 2017 30 Cr-DOPED ZnO Prepared by Solid State Reaction Method Kerista Sebayang 1 Saufa Taslima 1 Masno Ginting 2 Perdamean Sebayang 2 Nurdin Bukit 3 1.Departement of Physics, University of Sumatra Utara ,Indonesia 2.Laboratory of Advance Material Magnetic Research Center for Physics LIPI Serpong, Tanggerang Indonesia 3.Departement of Physics, State University of Medan,Indonesia Abstract In this paper, the effect of doped concentrations of Cr at ZnO powder has been studied using structur, magnetic and electrical properties has been investigated by X-Ray Diffractometer (XRD), Vibrating Sample Magnetometer (VSM), I-V and C-V measurements. The preparation of doped ZnO was using solid state reaction method with high speedshaker mill and continued with sintering at 900 0 C for 4 hours. Samples doped with Cr has polycrystalline hexagonal wurtzite structure with increasing Cr composition indicates the presence of impurity. From the results VSM of doping ZnO, Cr showed diamagnetic properties become paramagnetic. The results of the I-V and C-V meter Cr doped ZnO resistivity value increases ,decreases conductivity and dielectric constant decreases. Keywords: Cr , ZnO, Structur, Magnetic, Electrical properties 1. INTRODUCTION ZnO recently quite a lot of interest than GaN and is a promising material for ultraviolet (UV) LEDs and laser diodes, because it has a band gap (3:37 eV). ZnO has been predicted to maintain ferromagnetic properties at room temperature, ZnO doped with transition metals Mn, Fe, Co and Ni will become a ferromagnetic behavior. ZnO: TM is interesting not only in terms of room temperature ferromagnetic, Because the high energy gap, ZnO semiconductor very efficient in absorbing ultraviolet rays and emits blue light (Lojkowski et al., 2002). Because of these characteristics of semiconductor ZnO has potential there are many applications (Pivin J.C ., 2008). Previous studies (Prakash Chand et al., 2014, Yang Liu et al. 2010, Shubra Singh et al., 2008) suggests the addition of Cr doped affects the structure of the resulting crystals. Such changes result in magnetic and electrical properties. Several methods have been used for the fabrication of Cr doped ZnO as: thin films (Fu Chang-feng ,et al., 2010, Xiaolu Pang., 2011), sol gel (Yang Liu et al., 2010), chemical vapor synthesis (CVS) (Wei Jin et al., 2007), co-precipitation (Vishwanath Dattu et al., 2012). ZnO: Cr has been widely studied, but little is using solid state methods rection. However, the method of solid state reaction is less expensive, simple in preparation and could be more easily to scaled-up compared to some of the earlier methods of doping such as ion implantation and thin film deposition (Owens, 2009). In this study solid state reaction method is used for fabrication ZnO: Cr. Effects composition variation of doped on the structure, the nature of electricity and magnetism was studied using XRD, I-V meter, C-V meter and VSM. 2. RESEARCH METHODS The main material for this study was using source-based ceramic oxide (ZnO), while doping material (Fe and Cr) was used a pure metal. Doping concentrations were varied from 2.5 to 4.5% atom. The ZnO and Cr powders were mixed and milled in the cylindrical stainless steels with stainless steels ball, where the ratio of the powders and balls is 1: 10. That process is done by wet milling with the toluene as solvent for 3 hours. Afterwards, milled powders drayed on oven at 100°C for 3 hours. The result powders pressed in the bulk forms with diameter is 15 mm and thickness is 2mm. All samples synthesized by using aoutomatic axial hydrolic press with 1500 kgf/cm 2 . This Bulk sintered in temperature 900°C for 4 hours in air. The Phase and crystal parameters of sintered ceramic are identified by XRD using Cukα radiation (λ = 1.5406 Å), diffractometer (40 kV, 30 mA), Smartlab-Rigaku. I-V using FLUKE 8842A Multimeter and C-V meter were used to analyze the electrical properties. And the magnetic properties is measured using Vibrating Sample Magnetometer Oxford types VSM 1.2H . 3. RESULT AND DISCUSSION From Figure 1-a, it can be seen that the XRD patterns of ZnO doped with Cr has similarities with the XRD pattern of ZnO doped with Fe. This result is also confirms that ZnO doped with Cr has a wurtzite hexagonal structure (Didik Aryanto. et al ,2016) with the dominant peaks intensity at planes (100), (002) and (101) (JCPDS No. 00-005-0664). The appearance of ZnCr 2 O 4 secondary phase at ZnO doped with Cr is also found at angle 2θ of about 30.32°, 35.1° and 57.5° (JCPDS No. 01-087-0028). The increasing value of ion Cr dopant will affecting the number of Cr ion that insert themselves into the ZnO lattice. Which can be recognized by the increase of intensity peak (as shown in Figure 1-b). While details observation peak of ZnO at (002) plane, showed that there is also a shift to the greater value of 2θ (Figure 1-c). This can be indicated as the Cr ion is successfully