Materials Research Bulletin 42 (2007) 870–874
www.elsevier.com/locate/matresbu
Ternary metal nitrides by the urea route
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A. Gomathi
Chemistry and Physics Materials Unit and CSIR Centre of Excellence in Chemistry, Jawaharlal Nehru Centre
for Advanced Scientific Research, Jakkur P.O., Bangalore, Karnataka 560 064, India
Received 4 August 2006; received in revised form 17 August 2006; accepted 25 August 2006
Available online 29 September 2006
Abstract
Interstitial molybdenum ternary nitrides, M Mo N (M = Fe and Co, n = 3; M = Ni, n = 2), can be obtained by heating the
n
3
molybdate precursors, FeMoO
Co Mo N are obtained in pure form. The nickel nitride has the composition Ni
the nitrides have been characterized by various physical methods.
2006 Elsevier Ltd. All rights reserved.
4
, CoMoO
4
and NiMoO
4
with urea in the 1:12 molar ratio in the 900–1000 8C range. Fe
3 3
Mo N and
3
3
Mo N and therefore is in admixture with nickel. All
2 3
#
Keywords: A. Nitrides; B. Chemical synthesis
1
. Introduction
Ternary metal nitrides, such as alkaline earth silicon nitrides (MSiN with M = Ba, Sr, Ca), alkaline earth zinc
nitrides (Sr ZnN , Ba ZnN ) and nickel nitrides (Sr NiN and CaNiN) have been synthesized by various means. One
2
2
2
2
2
2
2
of the general procedures involves reacting a transition metal or a main group metal with an alkali or alkaline earth
nitride or amide [1–4]. An approach to synthesize ternary nitrides of the type MWN (M = Fe, Ni, Co) has been to heat
2
the respective ternary oxide precursor in NH [5–7]. The first metallic layered nitride, LiMoN , was synthesized by the
3
2
ammonolysis of either a molecular organometallic precursor or a ternary oxide [8]. Weil and Kumta [9] reported the
synthesis of Fe Mo N, FeWN , Ni Mo N and Ti AlN using complex precursors. Synthesis of Fe Mo N by the
ammonolysis of the oxide precursor has been reported [10]. The ternary nitride, Ni Mo N, has been prepared by
3
3
2
3
3
3
3
3
2
3
heating a metallorganic precursor in NH [11]. Alconchel et al. [12] have reported a study on the influence of
3
preparative variables on the ammonolysis of the molybdate precursors. Both the ammonolysis as well as the plasma
nitridation of FeMoO and CoMoO results in the respective intermetallic nitrides [13]. Synthesis of Fe Mo N and
Co Mo N by mechanochemical alloying and by the nitridation of the corresponding ternary carbide has also been
4
4
3
3
3
3
reported [14]. Prior et al. [15,16] have reported the synthesis of Ni2 M Mo N (M = Co, Pd) and Fe M Mo N
ꢀx
x
3
2ꢀx
x
3
(
M = Ni, Pd, Pt) by heating a stoichiometric mixture of the respective oxides under flowing synthesis gas.
Based on our recent success with the urea route to synthesize binary metal nitrides, such as BN, TiN and NbN [17],
we decided to examine whether this simple procedure can also be used to produce ternary nitrides. In this article, we
report the synthesis of interstitial molybdenum ternary nitrides, M Mo N (M = Fe and Co, n = 3; M = Ni, n = 2) by the
n
3
reaction of the respective ternary metal oxides with urea.
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