Single‐step preparation of rutile‐type CrNbO4 and CrTaO4 oxides from oxalate precursors–characterization and properties

Androš Dubraja, Lidija; Pajić, Damir; Vrankić, Martina; Dragović, Jure; Valant, Matjaz; Benčina, Metka; Jurić, Marijana (2019) Single‐step preparation of rutile‐type CrNbO4 and CrTaO4 oxides from oxalate precursors–characterization and properties. Journal of the American Ceramic Society, 102 . pp. 6697-6704. ISSN 0002-7820

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Abstract

Chromium niobate and tantalate (CrNbO4 and CrTaO4) were synthesized by pyrolysis of the oxalate‐based heterometallic complexes [Cr2(bpy)4(μ-O)4Nb2(C2O4)4]·3H 2O (Cr‐Nb) and [Cr(bpy)2(H2O)(μ‐O)Ta(C2O4)3]2·3.5H2O (Cr‐Ta) (bpy = 2, 2'‐bipyridine). Compared to conventional solid‐state synthesis, herein studied oxides are prepared at lower temperatures, in one step without repeating grinding procedures. The structure, morphology, and optical properties of the as‐synthesized oxides were characterized using powder X‐ray diffraction (PXRD), field emission scanning electron microscopy (SEM), the thermogravimetric and differential thermal analysis (TG/DTA) and UV‐vis diffuse reflectance spectroscopy (UV‐vis DRS). The determined band gap energies of CrNbO4 and CrTaO4 are 2.39 and 2.82 eV, respectively, which prompted us to investigate photocatalytic activity of these oxides in degradation of dyes. Microscopy studies show that the particles of both oxides began to aggregate into bigger particles, leading to an increase in grain size. Additionally, magnetization measurements on both oxides revealed spin‐glass behavior at low temperatures.

Item Type:	Article
Uncontrolled Keywords:	band gap ; decomposition ; magnetic materials/properties ; scanning electron microscopy ; X‐ray methods
Subjects:	NATURAL SCIENCES > Physics
Divisions:	Division of Materials Chemistry
Projects:	Project title Project leader Project code Project type Novi metal-organsi sustavi s oksalatnim i kinoidnim ligandima s podešenim svojstvima pogodnim za primjenu-NMOSBOQLWTPSFP Krešimir Molčanov IP-2014-09-4079 HRZZ Multiferični i magnetoelektrični sustavi-FerMaEl Damir Pajić UIP-2014-09-8276 HRZZ
Depositing User:	Marijana Jurić
Date Deposited:	05 May 2020 08:53
URI:	http://fulir.irb.hr/id/eprint/5645
DOI:	10.1111/jace.16521

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