Vol.:(0123456789) 1 3 Applied Physics A ( 2020) 126:761 https://doi.org/10.1007/s00339-020-03950-3 Micro‑structure, thermal, and dielectric performance of polyester nanocomposites containing nano‑Ni 0.5 Zn 0.5 Fe 2 O 4 T. A. Taha 1,2  · A. Hassona 2  · S. Elrabaie 2  · M. T. Attia 2 Received: 9 May 2020 / Accepted: 27 August 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract This manuscript aims to investigate the structural, thermal, and dielectric properties of polyester/Ni 0.5 Zn 0.5 Fe 2 O 4 nanocom- posites. The synthesized samples were characterized using X-ray difraction (XRD), Fourier transform infrared (FTIR), feld emission scanning electron microscope, transmission electron microscope (TEM), thermogravimetric analysis (TGA), and dielectric measurements. The XRD patterns confrmed the existence of both polyester and Ni 0.5 Zn 0.5 Fe 2 O 4 nanoparticles peaks. FTIR analysis confrmed the incorporation of Ni 0.5 Zn 0.5 Fe 2 O 4 nanoparticles into the polyester matrix in agreement with XRD results. SEM micrographs showed distribution of nanoparticles inside the polymer and TEM image showed a little agglomeration of Ni 0.5 Zn 0.5 Fe 2 O 4 with fake-like micrometer-sized particles. The incorporation of nanofller into the polymer increases the thermal stability as the weight losses reduced with nanoparticles content. Dielectric analysis depicted the enhancement in both real and imaginary parts of permittivity when nanoparticles concentration increased. Addition- ally, the AC conductivity increased while the electric impedance decreased with increasing Ni 0.5 Zn 0.5 Fe 2 O 4 concentration. Keywords Polyester · Nanocomposite · TGA  · Dielectric spectroscopy 1 Introduction Nowadays, hybrid materials from organic/inorganic materi- als gains intensive concern of researchers due to their unique properties [1–8]. Because of their capacity to behave as stabilizers or surface capping agents, organic polymers are great hosts for trapping metal and semiconductor nanopar- ticles. Due to the fascinating characteristics of nanosize and large surface area; nanoparticles are more attractive so, the polymer/nanofller composites presented properties better than conventional polymer composites [9–14]. Polyester is the fourth most produced polymer, account- ing for about 18% of world polymer manufacturing [15]. Recently, ferromagnetic particles integrated in polymer composites increasingly used as microwave absorbents at high frequencies [16–18]. NiZn ferrite has high saturation magnetization, notable chemical stability, and excellent mechanical strength as one of the most signifcant magnetic materials [19]. NiZn ferrite nanomaterials showed good results for the attenuation of electromagnetic waves [20]. The ferromagnetic NiZn ferrite nanomaterials are generally useful in electromagnetic (EM) wave absorption owing to its natural resonance for EMI shielding materials. Never- theless, their application is restricted by high density and hardness. Therefore, it continues a need for a comparatively lightweight, fexible, and efective NiZn ferrite composites for microwave absorption across broad spectrum of bands. Accordingly, magnetic composite materials generally pre- pared with ferro- and ferrimagnetic particles integrated in a polymer matrix are commonly used in electronic appli- ances and systems such as microwave transmitters, micro- wave inductors, and radio-absorbing materials [21–27]. Ni 0.5 Zn 0.5 Fe 2 O 4 nanoparticles showed promising dielec- tric constant, dielectric loss, and saturation magnetization as reported in our previous work [28]. Consequently, we selected this ferrite composition for preparing polyester nanocomposites in the present work. In this work, polyester/Ni 0.5 Zn 0.5 Fe 2 O 4 nanocomposites containing high concentrations up to 50 wt% were prepared by conventional solution casting method. The prepared * T. A. Taha taha.hemaida@yahoo.com 1 Physics Department, College of Science and Arts, Jouf University, P.O. Box 756, Al-Gurayyat, Saudi Arabia 2 Physics and Engineering Mathematics Department, Faculty of Electronic Engineering, Menoufa University, Menouf 32952, Egypt