Room Temperature Gas Sensing Properties of Sn-Substituted
Nickel Ferrite (NiFe
) Thin Film Sensors Prepared
by Chemical Co-Precipitation Method
and J. CHANDRASEKARAN
1.—Department of Physics, RVS Technical Campus, Coimbatore, Tamil Nadu 641402, India.
2.—School of Electronic Science and Technology, Dalian University of Technology, Dalian 116023,
People’s Republic of China. 3.—Center for Nanomaterial and Energy Devices, Swami Ramanand
Teerth Marathwada University, Dnyanteerth, Vishnupuri, Nanded 431606, India.
4.—Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science,
Coimbatore, Tamil Nadu 641 020, India. 5.—e-mail: email@example.com
Tin (Sn) substituted nickel ferrite (NiFe
) thin ﬁlm sensors were prepared
by a simple chemical co-precipitation method, which initially characterized
their structure and surface morphology with the help of x-ray diffraction and
scanning electron microscopy. Surface morphology of the sensing ﬁlms reveals
particles stick together with nearer particles and this formation leads to a
large speciﬁc area as a large speciﬁc area is very useful for easy adsorption of
gas molecules. Transmission electron microscopy and selected area electron
diffraction pattern images conﬁrm particle size and nanocrystallnity as due to
formation of circular rings. Fourier transform infrared analysis has supported
the presence of functional groups. The 3.69 eV optical band gap of the ﬁlm was
found which enabled better gas sensing. Gas sensors demonstrate better re-
sponse and recovery characteristics, and the maximum response was 68.43%.
Key words: Nanostructured ferrites, gas sensor, thin ﬁlm, surface
In recent decades, sulfur hexaﬂuoride has been
used in gas insulated switch gears mainly in power
electronics owing to its outstanding features like
small ﬂoor space, stability, reliability, insulation and
low cost. It is denser than air because of its robust
capture of oxygen and has a good dielectric strength.
Due to sufﬁcient dielectric strength, it is used as an
insulating medium. So, it is inevitable in gas insu-
lated switch gears.
The pure sulfur hexaﬂuoride is
nontoxic, colorless and non-ﬂammable. During the
ﬁlling of the target gas at pressure, it can be leaked.
The leaked gases can be easily mixed with oxygen,
leading to increased toxicity. The above mixtures of
gas release toxic gases like sulfur dioxide and
hydrogen ﬂuoride. Hence, sulfur hexaﬂuoride is
essential for electrical equipment and environmental
To date, numerous methods have been
used to detect sulfur hexaﬂuoride, and the methods
are namely gas chromatography, semiconductor gas
detection tubes and infrared absorption spectrome-
try. Decomposed low-level ﬂuorine sulﬁdes cannot be
detected through gas detection tubes. In gas chro-
matography, it takes more time for detection and
also ofﬂine testing is irremissible.
Mostly, thin ﬁlm
types of gas sensors are used in detection. However, a
thin ﬁlm gas sensor detects oxidizing and reducing
gas and a thick ﬁlm detects only reducing gases.
Speciﬁcally, transition-metal oxides with d0 and d10
electronic conﬁgurations are being used for gas
The d10 electronic conﬁgura-
tion is shown in the post-transition-metal oxide of tin
(Sn). Due to this reason, tin (Sn) elements can be
substituted in nickel ferrite ﬁlm.
(Received December 17, 2017; accepted April 10, 2018;
published online April 25, 2018)
Journal of ELECTRONIC MATERIALS, Vol. 47, No. 7, 2018
2018 The Minerals, Metals & Materials Society