Nickel Oxide (NiO) nanoparticles (NPs), doped with manganese (Mn) and cobalt (Co) at concentrations up to 8%, were synthesized using the composite hydroxide method (CHM). X-ray diffraction (XRD) analysis confirmed the formation of a cubic NiO structure, with no additional peaks detected, indicating successful doping. The average crystallite size was determined to range from 15 to 17.8 nm, depending on the dopant concentration. Scanning electron microscopy (SEM) images revealed mostly spherical, agglomerated particles, likely due to magnetic interactions. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the incorporation of Mn and Co into the NiO lattice, consistent with the XRD results. The dielectric properties exhibited a high dielectric constant at low frequencies, which can be attributed to ion jump orientation and space charge effects. The imaginary part of the dielectric constant decreased with increasing frequency, as it became harder for electrons to align with the alternating field at higher frequencies. Both the real and imaginary dielectric constants showed behavior consistent with Koop’s theory, increasing at low frequencies and decreasing at higher frequencies. Dielectric loss was primarily attributed to dipole flipping and charge migration. AC conductivity increased with frequency, and exhibited higher conductivity at high frequencies due to small polaron hopping. These co-doped NPs show potential for applications in solid oxide fuel cells.

1. Rajenimbalkar RS, Deshmukh VJ, Patankar KK, et al. Effect of multivalent ion doping on magnetic, electrical, and dielectric properties of nickel ferrite nanoparticles. Scientific Reports. 2024; 14(1): 29547. doi: 10.1038/s41598-024-81222-3

2. Miroshnichenko AE, Evlyukhin AB, Yu YF, et al. Nonradiating anapole modes in dielectric nanoparticles. Nature Communications. 2015; 6(1): 8069. doi: 10.1038/ncomms9069

3. Yang Y, Gao P, Li L, et al. Electrochemical dynamics of nanoscale metallic inclusions in dielectrics. Nature Communications. 2014; 5(1): 4232. doi: 10.1038/ncomms5232

4. Jahani S, Jacob Z. All-dielectric metamaterials. Nature Nanotechnology. 2016; 11(1): 23–36. doi: 10.1038/nnano.2015.304

5. Li X, He S, Jiang Y, et al. Unraveling bilayer interfacial features and their effects in polar polymer nanocomposites. Nature Communications. 2023; 14(1): 5707. doi: 10.1038/s41467-023-41479-0

6. Sharma V, Wang C, Lorenzini RG, et al. Rational design of all organic polymer dielectrics. Nature Communications. 2014; 5(1): 4845. doi: 10.1038/ncomms5845

7. Khan AA, Mathur A, Yin L, et al. Breaking dielectric dilemma via polymer functionalized perovskite piezocomposite with large current density output. Nature Communications. 2024; 15(1). doi: 10.1038/s41467-024-53846-6

8. Sagadevan S, Pal K, Chowdhury ZZ, et al. Structural, optical and dielectric investigation of CdFe2O4nanoparticles. Materials Research Express. 2017; 4(7): 075025. doi: 10.1088/2053-1591/aa77b5

9. Lin Z, Du C, Yan B, et al. Two-dimensional amorphous NiO as a plasmonic photocatalyst for solar H2 evolution. Nature Communications. 2018; 9(1): 4036. doi: 10.1038/s41467-018-06456-y

10. Ahmad S, Usman M, Hashim M, et al. Investigation of Optical and Dielectric Properties of Nickel-Doped Zinc Oxide Nanostructures Prepared via Coprecipitation Method. Lovergine N, ed. Nanomaterials and Nanotechnology. 2024; 2024: 1–11. doi: 10.1155/2024/8330886

11. Sharma V, Chotia C, Tarachand T, et al. Influence of particle size and dielectric environment on the dispersion behaviour and surface plasmon in nickel nanoparticles. Physical Chemistry Chemical Physics. 2017; 19(21): 14096–14106. doi: 10.1039/c7cp01769c

12. Thongbai P, Tangwancharoen S, Yamwong T, et al. Dielectric relaxation and dielectric response mechanism in (Li, Ti)-doped NiO ceramics. Journal of Physics: Condensed Matter. 2008; 20(39): 395227. doi: 10.1088/0953-8984/20/39/395227

13. Hajalilou A, Kamari HM, Shameli K. Dielectric and electrical characteristics of mechanically synthesized Ni-Zn ferrite nanoparticles. Journal of Alloys and Compounds. 2017; 708: 813–826. doi: 10.1016/j.jallcom.2017.03.030

14. Sharma A, Hickman J, Gazit N, et al. Nickel nanoparticles set a new record of strength. Nature Communications. 2018; 9(1). doi: 10.1038/s41467-018-06575-6

15. Gong M, Zhou W, Tsai MC, et al. Nanoscale nickel oxide/nickel heterostructures for active hydrogen evolution electrocatalysis. Nature Communications. 2014; 5(1): 4695. doi: 10.1038/ncomms5695

16. Cheng S, Sheng D, Mukherjee S, et al. Carbon nanolayer-mounted single metal sites enable dipole polarization loss under electromagnetic field. Nature Communications. 2024; 15(1): 9077. doi: 10.1038/s41467-024-53465-1

17. Singh S, Verma R, Kaul N, et al. Surface plasmon-enhanced photo-driven CO2 hydrogenation by hydroxy-terminated nickel nitride nanosheets. Nature Communications. 2023; 14(1): 2551. doi: 10.1038/s41467-023-38235-9

18. Wang H, Liang Y, Gong M, et al. An ultrafast nickel–iron battery from strongly coupled inorganic nanoparticle/nanocarbon hybrid materials. Nature Communications. 2012; 3(1): 917. doi: 10.1038/ncomms1921

19. Neagu D, Oh TS, Miller DN, et al. Nano-socketed nickel particles with enhanced coking resistance grown in situ by redox exsolution. Nature Communications. 2015; 6(1): 8120. doi: 10.1038/ncomms9120

20. Suryanto BHR, Wang Y, Hocking RK, et al. Overall electrochemical splitting of water at the heterogeneous interface of nickel and iron oxide. Nature Communications. 2019; 10(1): 5599. doi: 10.1038/s41467-019-13415-8

21. Li HB, Yu MH, Wang FX, et al. Amorphous nickel hydroxide nanospheres with ultrahigh capacitance and energy density as electrochemical pseudocapacitor materials. Nature Communications. 2013; 4(1): 1894. doi: 10.1038/ncomms2932

22. Fan L, Liu PF, Yan X, et al. Atomically isolated nickel species anchored on graphitized carbon for efficient hydrogen evolution electrocatalysis. Nature Communications. 2016; 7(1):10667. doi: 10.1038/ncomms10667

23. Wang H, Lee HW, Deng Y, et al. Bifunctional non-noble metal oxide nanoparticle electrocatalysts through lithium-induced conversion for overall water splitting. Nature Communications. 2015; 6(1): 7261. doi: 10.1038/ncomms8261

24. Yun G, Tang SY, Sun S, et al. Liquid metal-filled magnetorheological elastomer with positive piezoconductivity. Nature Communications. 2019; 10(1): 1300. doi: 10.1038/s41467-019-09325-4

25. Zhou H, Yu F, Huang Y, et al. Efficient hydrogen evolution by ternary molybdenum sulfoselenide particles on self-standing porous nickel diselenide foam. Nature Communications. 2016; 7(1): 12765. doi: 10.1038/ncomms12765

26. Ali S, Khalid M, Nazir G, et al. Effect of nickel substitution on structural and dielectric properties of Mg-Zn based spinel ferrite nanoparticles. Physica Scripta. 2022; 97(6): 065802. doi: 10.1088/1402-4896/ac690f

27. Jiang J, Zhu J, Ai W, et al. Encapsulation of sulfur with thin-layered nickel-based hydroxides for long-cyclic lithium–sulfur cells. Nature Communications. 2015; 6(1): 8622. doi: 10.1038/ncomms9622

28. Qiu H, Xu T, Wang Z, et al. Hopping transport through defect-induced localized states in molybdenum disulphide. Nature Communications. 2013; 4(1): 2642. doi: 10.1038/ncomms3642

29. Kobayashi N, Masumoto H, Takahashi S, et al. Giant dielectric and magnetoelectric responses in insulating nanogranular films at room temperature. Nature Communications. 2014; 5(1): 4417. doi: 10.1038/ncomms5417

30. Rehman AU, Atif M, Rehman U ur, et al. Tuning the magnetic and dielectric properties of Fe3O4 nanoparticles for EMI shielding applications by doping a small amount of Ni2+/Zn2+. Materials Today Communications. 2023; 34: 105454. doi: 10.1016/j.mtcomm.2023.105454

31. Deonikar VG, Kulkarni VD, Rathod SM, et al. Fabrication and characterizations of structurally engineered lanthanum substituted nickel-cobalt ferrites for the analysis of electric and dielectric properties. Inorganic Chemistry Communications. 2020; 119: 108074. doi: 10.1016/j.inoche.2020.108074

32. Narender SS, Varma VVS, Srikar CS, et al. Nickel Oxide Nanoparticles: A Brief Review of Their Synthesis, Characterization, and Applications. Chemical Engineering & Technology. 2022; 45(3): 397–409. doi: 10.1002/ceat.202100442

33. Imran Din M, Rani A. Recent Advances in the Synthesis and Stabilization of Nickel and Nickel Oxide Nanoparticles: A Green Adeptness. International Journal of Analytical Chemistry. 2016; 2016: 1–14. doi: 10.1155/2016/3512145

34. Aamir MF, Mumtaz M, Saqib I, et al. Temperature driven shifts of super-conductance in Zn-doped CuTl-1223 nanoparticle. Journal of Materials Science: Materials in Electronics. 2024; 35(33): 1–12. doi: 10.1007/s10854-024-13848-y

35. Li Y, Fang L, Liu L, et al. Giant dielectric response and charge compensation of Li- and Co-doped NiO ceramics. Materials Science and Engineering: B. 2012; 177(9): 673–677. doi: 10.1016/j.mseb.2012.03.054

36. Dakhel AA. Dielectric relaxation behaviour of Li and La co-doped NiO ceramics. Ceramics International. 2013; 39(4): 4263–4268. doi: 10.1016/j.ceramint.2012.10.278

37. Manna S, De SK. Giant dielectric permittivity observed in Li and Zr co-doped NiO. Solid State Communications. 2010; 150(9–10): 399–404. doi: 10.1016/j.ssc.2009.11.044

38. Abdallah AM, Noun M, Awad R. Dielectric, impedance and conductivity properties of pristine and (Gd, Ru)-dual doped NiO nanoparticles. Journal of Alloys and Compounds. 2022; 910: 164952. doi: 10.1016/j.jallcom.2022.164952

39. Shaikh A, Bellad S, Chougule B. Temperature and frequency-dependent dielectric properties of Zn substituted Li–Mg ferrites. Journal of magnetism and magnetic materials. 1999; 195(2): 384–390.

40. Bhunia AK, Pradhan SS, Bhunia K, et al. Study of the optical properties and frequency-dependent electrical modulus spectrum to the analysis of electric relaxation and conductivity effect in zinc oxide nanoparticles. Journal of Materials Science: Materials in Electronics. 2021; 32(17): 22561–22578. doi: 10.1007/s10854-021-06742-4

41. Kaur J, Gupta V, Kotnala R, et al. Size dependent dielectric properties of Co and Fe doped SnO 2 nanoparticles and their nanorods by Ce co-doping. Materials Science, Physics; 2012.

42. Yücedağ İ, Kaya A, Altındal Ş. On the frequency dependent negative dielectric constant behavior in Al/Co-doped (PVC+TCNQ)/p-Si structures. International Journal of Modern Physics B. 2014; 28(23): 1450153. doi: 10.1142/s0217979214501537

43. Bharathy G, Raji P. Pseudocapacitance of Co doped NiO nanoparticles and its room temperature ferromagnetic behavior. Physica B: Condensed Matter. 2018; 530: 75–81. doi: 10.1016/j.physb.2017.10.106

44. Jothibas M, Bharanidharan K, Paulson E, et al. Effect of co-dopant proportion on the structural, optical and magnetic properties of pristine NiO nanoparticles synthesized by Sol–gel method. Journal of Materials Science: Materials in Electronics. 2022; 33: 907–919.

45. Rahman NU, Khan WU, Khan S, et al. A promising europium-based down conversion material: organic–inorganic perovskite solar cells with high photovoltaic performance and UV-light stability. Journal of Materials Chemistry A. 2019; 7(11): 6467–6474. doi: 10.1039/c9ta00551j

46. Rahman NU, Khan WU, Li W, et al. Simultaneous enhancement in performance and UV-light stability of organic–inorganic perovskite solar cells using a samarium-based down conversion material. Journal of Materials Chemistry A. 2019; 7(1): 322–329. doi: 10.1039/c8ta09362h

47. Shakoor A, Aman Nowsherwan G, Fasih Aamir M, et al. Performance Evaluation of Solar Cells by Different Simulating Softwares. Solar PV Panels—Recent Advances and Future Prospects; 2023.

48. Gallo AB, Simões-Moreira JR, Costa HKM, et al. Energy storage in the energy transition context: A technology review. Renewable and Sustainable Energy Reviews. 2016; 65: 800–822. doi: 10.1016/j.rser.2016.07.028

49. Waqas M, Shakoor A, Nadeem M, et al. Unveiling transport properties in rare-earth-substituted nanostructured bismuth telluride for thermoelectric application. Zeitschrift für Naturforschung A. 2023; 78(11): 1069–1080. doi: 10.1515/zna-2023-0162

50. Long Y, Xian Y, Yuan S, et al. π-π conjugate structure enabling the channel construction of carrier-facilitated transport in 1D–3D multidimensional CsPbI2Br solar cells with high stability. Nano Energy. 2021; 89: 106340. doi: 10.1016/j.nanoen.2021.106340

51. Takashima S, Schwan HP. Dielectric Dispersion of Crystalline Powders of Amino Acids, Peptides, and Proteins1. The Journal of Physical Chemistry. 1965; 69(12): 4176–4182. doi: 10.1021/j100782a019

52. Ishii K, Kinoshita M, Kuroda H. Dielectric Constant Measurement on Organic Crystalline Powder. Bulletin of the Chemical Society of Japan. 1973; 46(11): 3385–3391. doi: 10.1246/bcsj.46.3385

53. Aly K. Adjusting the relation between the imaginary part of the dielectric constant and the wavelength. Physica B: Condensed Matter. 2023; 655: 414723. doi: 10.1016/j.physb.2023.414723

54. Murtanto TB, Natori S, Nakamura J, et al. ac conductivity and dielectric constant of conductor-insulator composites. Physical Review B. 2006; 74(11). doi: 10.1103/physrevb.74.115206

55. Hill R, Jonscher A. DC and AC conductivity in hopping electronic systems. Journal of Non-Crystalline Solids. 1979; 32(1–3): 53–69.