Impedance Spectroscopic Study of Nickel Sulfide Nanostructures Deposited by Aerosol Assisted Chemical Vapor Deposition Technique

• Main Authors: Sadia Iram, Azhar Mahmood, Muhammad Fahad Ehsan, Asad Mumtaz, Manzar Sohail, Effat Sitara, Syeda Aqsa Batool Bukhari, Sumia Gul, Syeda Arooj Fatima, Muhammad Zarrar Khan, Rubina Shaheen, Sajid Nawaz Malik, Mohammad Azad Malik
• Format: Article
• Language: English
• Published: MDPI AG 2021-04-01
• Series: Nanomaterials
• Subjects: nickel chalcogenide; AACVD; dielectric behavior; impedance spectroscopy
• Online Access: https://www.mdpi.com/2079-4991/11/5/1105

This research aims to synthesize the <i>Bis</i>(di-<i>iso</i>butyldithiophosphinato) nickel (II) complex [Ni(iBu₂PS₂)] to be employed as a substrate for the deposition of nickel sulfide nanostructures, and to investigate its dielectric and impedance characteristics for applications in the electronic industry. Various analytical tools including elemental analysis, mass spectrometry, IR, and TGA were also used to further confirm the successful synthesis of the precursor. NiS nanostructures were grown on the glass substrates by employing an aerosol assisted chemical vapor deposition (AACVD) technique via successful decomposition of the synthesized complex under variable temperature conditions. XRD, SEM, TEM, and EDX methods were well applied to examine resultant nanostructures. Dielectric studies of NiS were carried out at room temperature within the 100 Hz to 5 MHz frequency range. Maxwell-Wagner model gave a complete explanation of the variation of dielectric properties along with frequency. The reason behind high dielectric constant values at low frequency was further endorsed by Koops phenomenological model. The efficient translational hopping and futile reorientation vibration caused the overdue exceptional drift of ac conductivity (σ_ac) along with the rise in frequency. Two relaxation processes caused by grains and grain boundaries were identified from the fitting of a complex impedance plot with an equivalent circuit model (R_g C_g) (R_gb Q_gb C_gb). Asymmetry and depression in the semicircle having center present lower than the impedance real axis gave solid justification of dielectric behavior that is non-Debye in nature.