New nanoparticulate Gd 1x Zr x Fe 1y Mn y O 3 multiferroics: Synthesis, characterization and evaluation of electrical, dielectric and magnetic parameters Aneela Sultan a , Azhar Mahmood a , Nazia K. Goraya b , Ashfaq M. Qureshi b , Iqbal Ahmad c , Muhammad N. Ashiq b,⇑ , Imran Shakir d , Muhammad F. Warsi a,⇑ a Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan b Institute of Chemical Sciences, Bahauddin Zakariya University, Multan 60880, Pakistan c Department of Chemistry, University of Gujrat, Gujrat, Pakistan d Deanship of Scientific Research, College of Engineering, PO Box 800, King Saud University, Riyadh 11421, Saudi Arabia article info Article history: Received 19 September 2013 Received in revised form 1 October 2013 Accepted 3 October 2013 Available online 12 October 2013 Keywords: Nanostructures Chemical synthesis Dielectric properties Electrical properties Magnetic materials abstract Nanoparticles of Gd 1x Zr x Fe 1y Mn y O 3 (x, y = 0–1) were synthesized by micro-emulsion method. The struc- tural elucidation was accomplished by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis that confirmed that all the nanopar- ticles are crystalline in orthorhombic phase. The particles size was found in the range 12–48 nm (deter- mined by XRD) and 33–48 nm (estimated by SEM). The nanoparticles were then evaluated for electrical, dielectric and magnetic properties. The electrical resistivity studies exhibited the transition between metal to semiconductor in the range 340–380 K, besides overall electrical resistivity was decreased with the increased Zr–Mn contents. The maximum electrical resistivity (80.95  10 8 X cm) was exhibited by Gd 0.75 Zr 0.25 Fe 0.75 Mn 0.25 O 3 nanoparticles. The dielectric behavior was found to increase with increased Zr–Mn contents. The magnetic behavior confirmed the transition of magnetic order from antiferromag- netic to the ferromagnetic as the Zr and Mn contents were increased. The new structurally stable nano- structured multiferroics can be utilized for fabricating high frequency and magnetic recording devices. Ó 2013 Elsevier B.V. All rights reserved. 1. Introduction Nanomaterials are a new class of advanced multifunctional materials that show very interesting and fascinating properties considerably different from the respective bulk materials [1–3]. For example the surface plasmon band, a characteristic property of metal nanoparticles, is not exhibited by the bulk metals [4]. Therefore nano-science and nanotechnology have attracted a sig- nificant number of scientists of all disciplines since last two dec- ades [5–7]. Among various nanomaterials, the transition metal oxides have a wide range of applications due to inherent rich chemistry that is attributed to their variable oxidation state. Further, ferrites, the metal oxides that contain more than 50% iron, have very important technological applications like in telecommu- nication, microwave devices etc [8–12]. The perovskites are another class of metal oxides with potential applications as electrode materials in fabrication of energy storage related devices [13,14]. Researchers are always searching a single material that possesses as much different functionalities as possible. To enhance the applications spectrum and meet the new generation needs, nanostructured metal oxides are under extensive research. Metal oxides are important because they have versatile applications. For example LiMn 2 O 4 and its derivatives have been evaluated for applications as electrode materials in Li-ion batteries [15]. On the other hand, several metal oxides are reported as dielectric materi- als that have applications in high frequency devices [16,17]. Here in this article, we report the GdFeO 3 system and its deriv- atives i.e. Gd 1x Zr x Fe 1y Mn y O 3 in the nanoscale range for evalua- tion of their dielectric and magnetic behavior. The main purpose of the study is to observe the effect of Zr and Mn substitution on the crystalline structure as well as on various physical, electrical, dielectric and magnetic behaviors of nanostructured perovskites. 2. Experimental 2.1. Materials/chemicals The chemicals used for the synthesis of GdFeO 3 and its Zr–Mn substituted derivatives were GdCl 3 6H 2 O (Sigma–Aldrich, 99%), Fe(NO 3 ) 3 9H 2 O (Sigma–Aldrich, 98%), MnCl 2 4H 2 O (Sigma–Aldrich, 99%), ZrOCl 2 4H 2 O (BDH, 96%), Cetlytrimethy- lammonium bromide (CTAB) (Fluka, 98%) and aqueous ammonia (BDH, 35%). These chemicals were used as such without any further treatment. 0925-8388/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jallcom.2013.10.018 ⇑ Corresponding authors. Tel.: +92 (0) 3455411391; fax: +92 (0) 62 92 55474. E-mail address: farooq.warsi@iub.edu.pk (M.F. Warsi). Journal of Alloys and Compounds 585 (2014) 790–794 Contents lists available at ScienceDirect Journal of Alloys and Compounds journal homepage: www.elsevier.com/locate/jalcom