Optical, Photocatalytic and Magnetic Properties of ZnO Nanostructures Prepared by Thermal Decomposition
Main Article Content
Abstract
ZnO nanostructures have been fabricated by annealing zinc acetate dihydrate at different temperatures (Tan). Thermogravimetric analysis, and XRD and Raman studies indicate ZnO crystals formed at above 250 oC. An increase of Tan would enhance the XRD intensity and number of Raman modes characteristic of hexagonal ZnO. Below 700 oC, the samples are mainly nanorods with the diameters and lengths of 50 –100 nm and 250 – 500 nm, respectively. As Tan increases from 700 to 1,200 oC, nanorods transform to irregular particles with average sizes of 0.2 – 2 mm. This influences the intensity ratio of UV-to-visible emissions. Though all the samples exhibit diamagnetism, several samples with Tan = 500 – 700 oC have additionally weak ferromagnetic order. Assessing RhB photodegradation has demonstrated the Tan = 300 oC sample showing the best photocatalyticity.
Keywords:
ZnO nanoparticles, thermal decomposition, optical/photocatalytic behaviors.
References
[1] Y. Chen, Y. Liu, P. Moradifar, A. J. Glaid, J. L. Russell, P. Mahale, S. Y. Yu, T. E. Culp, M. Kumar, E. D. Gomez, S. E. Mohney, T. E. Mallouk, N. Alem, J. V. Badding, Y. Liu, Quantum Transport in Three-dimensional Metalattices of Platinum Featuring an Unprecedentedly Large Surface Area to Volume Ratio, Phys. Rev. Mater., Vol. 4, 2020, pp. 035201, https://doi.org/10.1103/PhysRevMaterials.4.035201.
[2] C. K. Ghosh, Quantum Effect on Properties of Nanomaterials, in: Sengupta, A., Sarkar, C. (eds) Introduction to Nano. Engineering Materials, Springer, Berlin, Heidelberg, 2015, pp. 73-111, https://doi.org/10.1007/978-3-662-47314-6_5.
[3] K. J. Balkus, Metal Oxide Nanotube, Nanorod, and Quantum Dot Photocatalysis, in: New Futur. Dev. Catal., Elsevier, 2013, pp. 213-244, https://doi.org/10.1016/B978-0-444-53874-1.00009-3.
[4] V. Avrutin, N. Izyumskaya, Ü. Özgür, D. J. Silversmith, H. Morkoç, Ferromagnetism in ZnO- and GaN-based Diluted Magnetic Semiconductors: Achievements and Challenges, Proc. IEEE, Vol. 98, 2010, pp. 1288-1301, https://doi.org/10.1109/JPROC.2010.2044966.
[5] R. Yang, F. Wang, J. Lu, Y. Lu, B. Lu, S. Li, Z. Ye, ZnO with P-type Doping: Recent Approaches and Applications, ACS Appl. Electron. Mater., Vol. 5, 2023, pp. 4014-4034, https://doi.org/10.1021/acsaelm.3c00515.
[6] H. Jang, D. K. Kwon, D. H. Kim, J. M. Myoung, Characteristics of Flexible ZnO Nanorod UV Photodetectors Processed by Using a Direct Silicon Etching Transfer Method, J. Mater. Chem. C., Vol. 10, 2022, pp. 6805-6811, https://doi.org/10.1039/D2TC00377E.
[7] D. N. Petrov, N. T. Dang, N. D. Co, B. D. Tu, N. D. Lam, T. V. Quang, V. Q. Nguyen, J. H. Lee, B. T. Huy, D. S. Yang, D. T. Khan, T. L. Phan, Enhanced Photocatalytic Activity and Ferromagnetic Ordering in Hydrogenated Zn1−xCoxO, J. Mater. Sci., Vol. 59, 2024, pp. 9217-9236, https://doi.org/10.1007/s10853-024-09724-z.
[8] T. D. Pham, T. T. T. Truong, H. L. Nguyen, L. B. L. Hoang, V. P. Bui, T. T. M. Tran, T. D. Dinh, T. D. Le, Synthesis and Characterization of Novel Core–Shell ZnO@SiO2 Nanoparticles and Application in Antibiotic and Bacteria Removal, ACS Omega., Vol. 7, 2022, pp. 42073-42082, https://doi.org/10.1021/acsomega.2c04226.
[9] A. K. Srivastava, J. S. Tawale, R. Verma, D. Agarwal, C. Sharma, A. Kumar, M. K. Gupta, Morphological Evolution Driven Semiconducting Nanostructures for Emerging Solar, Biological and Nanogenerator Applications, Mater. Adv., Vol. 3, 2022, pp. 8030-8062, https://doi.org/10.1039/D2MA00683A.
[10] T. L. Phan, S. C. Yu, R. Vincent, H. M. Bui, T. D. Thanh, V. D. Lam, Y. P. Lee, Influence of Mn Doping on Structural, Optical, and Magnetic Properties of Zn1−xMnxO Nanorods, J. Appl. Phys., Vol. 108, 2010, pp. 044910, https://doi.org/10.1063/1.3478709.
[11] A. A. M. Raub, R. Bahru, S. N. A. M. Nashruddin, J. Yunas, A Review on Vertical Aligned Zinc Oxide Nanorods: Synthesis Methods, Properties, and Applications, J. Nanoparticle Res., Vol. 26, 2024, pp. 186, https://doi.org/10.1007/s11051-024-06098-w.
[12] C. C. Lin, Y. Y. Li, Synthesis of ZnO Nanowires by Thermal Decomposition of Zinc Acetate Dihydrate, Mater. Chem. Phys., Vol. 113, 2009, pp. 334-337, https://doi.org/10.1016/j.matchemphys.2008.07.070.
[13] G. L. Mar, P. Y. Timbrell, R. N. Lamb, Formation of Zinc Oxide Thin Films by the Thermal Decomposition of Zinc Zcetate, In: Howe, R. F., Lamb, R. N., Wandelt, K. (eds) Surface Science. Springer Proceedings in Physics, vol 73. Springer, Berlin, Heidelberg, 1993, pp. 177-192, https://doi.org/10.1007/978-3-642-84933-6_15.
[14] R. Saravanan, E. Thirumal, V .K. Gupta, V. Narayanan, A. Stephen, The Photocatalytic Activity of ZnO Prepared by Simple Thermal Decomposition Method at Various Temperatures, J. Mol. Liq., Vol. 177, 2013, pp. 394-401, https://doi.org/10.1016/j.molliq.2012.10.018.
[15] P. Katekaew, A. Prasatkhetragarn, R. Sirirak, C. Boonruang, A. Klinbumrung, Role of the Thermal Regime in the Defect Formation of Zinc Oxide Nanostructures Prepared by the Thermal Decomposition Process, Zeitschrift Für Phys. Chemie., Vol. 237, 2023, pp. 1077-1104, https://doi.org/10.1515/zpch-2023-0235.
[16] S. K. Nikhil, A. Das, M. Kumar P, M. Bhagavathiachari, R.G. Nair, Effect of Aspect Ratio of c-axis Oriented ZnO Nanorods on Photoelectrochemical Performance and Photoconversion Efficiency, Opt. Mater. (Amst)., Vol. 121, 2021, pp. 111551, https://doi.org/10.1016/j.optmat.2021.111551.
[17] A. Das, R. G. Nair, Effect of Aspect Ratio on Photocatalytic Performance of Hexagonal ZnO Nanorods, J. Alloys Compd., Vol. 817, 2020, pp. 153277, https://doi.org/10.1016/j.jallcom.2019.153277.
[18] F. C. Tsao, J. Y. Chen, C. H. Kuo, G. C. Chi, C. J. Pan, P. J. Huang, C. J. Tun, B. J. Pong, T. H. Hsueh, C. Y. Chang, S. J. Pearton, F. Ren, Residual Strain in ZnO Nanowires Grown by Catalyst-free Chemical Vapor Deposition on GaN/Sapphire (0001), Appl. Phys. Lett., Vol. 92, 2008, pp. 203110, https://doi.org/10.1063/1.2936090.
[19] R. Cuscó, E. A. Lladó, J. Ibáñez, L. Artús, J. Jiménez, B. Wang, M. J. Callahan, Temperature Dependence of Raman Scattering in ZnO, Phys. Rev. B., Vol. 75, 2007, pp. 165202, https://doi.org/10.1103/PhysRevB.75.165202.
[20] R. Zhang, P. G. Yin, N. Wang, L. Guo, Photoluminescence and Raman Scattering of ZnO Nanorods, Solid State Sci., Vol. 11, 2009, pp. 865-869, https://doi.org/10.1016/j.solidstatesciences.2008.10.016.
[21] M. Šćepanović, M. G. Brojčin, K. Vojisavljević, S. Bernik, T. Srećković, Raman Study of Structural Disorder in ZnO Nanopowders, J. Raman Spectrosc., Vol. 41, 2010, pp. 914-921, https://doi.org/10.1002/jrs.2546.
[22] V. Russo, M. Ghidelli, P. Gondoni, C. S. Casari, A. L. Bassi, Multi-wavelength Raman Scattering of Nanostructured Al-doped Zinc Oxide, J. Appl. Phys, Vol. 115, 2014, https://doi.org/10.1063/1.4866322.
[23] A. Mondal, S. Pal, A. Sarkar, T. S. Bhattacharya, S. Pal, A. Singha, S. K. Ray, P. Kumar, D. Kanjilal, D. Jana, Raman Investigation of N‐implanted ZnO: Defects, Disorder and Recovery, J. Raman Spectrosc., Vol. 50, 2019, pp. 1926-1937, https://doi.org/10.1002/jrs.5732.
[24] T. L. Phan, T. A. Ho, N. T. Dang, M. C. Nguyen, V. D. Dao, Electronic Structure, Optical and Magnetic Studies of PLD-grown (Mn, P)-doped ZnO Nanocolumns at Room Temperature, J. Phys. D. Appl. Phys., Vol. 50, 2017, pp. 295002, https://doi.org/10.1088/1361-6463/aa75e5.
[25] A. Samavati, A. F. Ismail, H. Nur, Z. Othaman, M. K. Mustafa, Spectral Features and Antibacterial Properties of Cu-doped ZnO Nanoparticles Prepared by Sol-gel Method, Chinese Phys. B., Vol. 25, 2016, pp. 077803, https://doi.org/10.1088/1674-1056/25/7/077803.
[26] N. A. Martynova, S. T. Umedov, L. S. Lepnev, M. Y. Komarova, A. V. Grigorieva, Electrochemicaly Formed ZnO and Au/ZnO Opal Films, SN Appl. Sci., Vol. 2, 2020, https://doi.org/10.1007/s42452-020-2341-z.
[27] P. A. Rodnyi, K. A. Chernenko, I. D. Venevtsev, Mechanisms of ZnO Luminescence in the Visible Spectral Region, Opt. Spectrosc. Vol. 125, 2018, pp. 357-363, https://doi.org/10.1134/S0030400X18090205.
[28] B. Lin, Z. Fu, Y. Jia, Green Luminescent Center in Undoped Zinc Oxide Films Deposited on Silicon Substrates, Appl. Phys. Lett., Vol. 79, 2001, pp. 943-945, https://doi.org/10.1063/1.1394173.
[29] T. E. Murphy, K. Moazzami, J. D. Phillips, Trap-related Photoconductivity in ZnO Epilayers, J. Electron. Mater., Vol. 35, 2006, pp. 543-549, https://doi.org/10.1007/s11664-006-0097-x.
[30] Y. W. Heo, D. P. Norton, S. J. Pearton, Origin of Green Luminescence in ZnO Thin Film grown by Molecular-Beam Epitaxy, J. Appl. Phys., Vol. 98, 2005, https://doi.org/10.1063/1.2064308.
[31] F. Wen, W. Li, J. H. Moon, J. H. Kim, Hydrothermal Synthesis of ZnO:Zn with Green Emission at Low Temperature with Reduction Process, Solid State Commun., Vol. 135, 2005, pp. 34-37, https://doi.org/10.1016/j.ssc.2005.03.066.
[32] I. Musa, N. Qamhieh, S. T. Mahmoud, Synthesis and Length Dependent Photoluminescence Property of Zinc Oxide Nanorods, Results Phys., Vol. 7, 2017, pp. 3552-3556, https://doi.org/10.1016/j.rinp.2017.09.035.
[33] S. Jayswal, R. S. Moirangthem, Thermal Decomposition Route to Synthesize ZnO Nanoparticles for Photocatalytic Application, in, 2018, pp. 020023, https://doi.org/10.1063/1.5052092.
[34] E. Tóthová, M. Senna, A. Yermakov, J. Kováč, E. Dutková, M. Hegedüs, M. Kaňuchová, M. Baláž, Z. L. Bujňáková, J. Briančin, P. Makreski, Zn Source-dependent Magnetic Properties of Undoped ZnO Nanoparticles from Mechanochemically Derived Hydrozincite, J. Alloys Compd., Vol. 787, 2019, pp. 1249-1259, https://doi.org/10.1016/j.jallcom.2019.02.149.
[35] T. L. Phan, Y. D. Zhang, D. S. Yang, N. X. Nghia, T. D. Thanh, S. C. Yu, Defect-induced Ferromagnetism in ZnO Nanoparticles Prepared by Mechanical Milling, Appl. Phys. Lett., Vol. 102, 2013, pp. 072408, https://doi.org/10.1063/1.4793428.
[36] J. M. D. Coey, Ferromagnetism, Solid State Sci., Vol. 7, 2005, pp. 660-667, https://doi.org/10.1016/j.solidstatesciences.2004.11.012.
[37] B. B. Straumal, S. G. Protasova, A. A. Mazilkin, E. Goering, G. Schütz, P. B. Straumal, B. Baretzky, Ferromagnetic Behaviour of ZnO: the Role of Grain Boundaries, Beilstein J. Nanotechnol., Vol. 7, 2016, pp. 1936-1947, https://doi.org/10.3762/bjnano.7.185.
[38] W. Q. Li, J. X. Cao, J. W. Ding, X. Hu, Modulating Magnetism of ZnO:C with Vacancy and Substitution, J. Appl. Phys., Vol. 110, 2011, https://doi.org/10.1063/1.3666051.
[2] C. K. Ghosh, Quantum Effect on Properties of Nanomaterials, in: Sengupta, A., Sarkar, C. (eds) Introduction to Nano. Engineering Materials, Springer, Berlin, Heidelberg, 2015, pp. 73-111, https://doi.org/10.1007/978-3-662-47314-6_5.
[3] K. J. Balkus, Metal Oxide Nanotube, Nanorod, and Quantum Dot Photocatalysis, in: New Futur. Dev. Catal., Elsevier, 2013, pp. 213-244, https://doi.org/10.1016/B978-0-444-53874-1.00009-3.
[4] V. Avrutin, N. Izyumskaya, Ü. Özgür, D. J. Silversmith, H. Morkoç, Ferromagnetism in ZnO- and GaN-based Diluted Magnetic Semiconductors: Achievements and Challenges, Proc. IEEE, Vol. 98, 2010, pp. 1288-1301, https://doi.org/10.1109/JPROC.2010.2044966.
[5] R. Yang, F. Wang, J. Lu, Y. Lu, B. Lu, S. Li, Z. Ye, ZnO with P-type Doping: Recent Approaches and Applications, ACS Appl. Electron. Mater., Vol. 5, 2023, pp. 4014-4034, https://doi.org/10.1021/acsaelm.3c00515.
[6] H. Jang, D. K. Kwon, D. H. Kim, J. M. Myoung, Characteristics of Flexible ZnO Nanorod UV Photodetectors Processed by Using a Direct Silicon Etching Transfer Method, J. Mater. Chem. C., Vol. 10, 2022, pp. 6805-6811, https://doi.org/10.1039/D2TC00377E.
[7] D. N. Petrov, N. T. Dang, N. D. Co, B. D. Tu, N. D. Lam, T. V. Quang, V. Q. Nguyen, J. H. Lee, B. T. Huy, D. S. Yang, D. T. Khan, T. L. Phan, Enhanced Photocatalytic Activity and Ferromagnetic Ordering in Hydrogenated Zn1−xCoxO, J. Mater. Sci., Vol. 59, 2024, pp. 9217-9236, https://doi.org/10.1007/s10853-024-09724-z.
[8] T. D. Pham, T. T. T. Truong, H. L. Nguyen, L. B. L. Hoang, V. P. Bui, T. T. M. Tran, T. D. Dinh, T. D. Le, Synthesis and Characterization of Novel Core–Shell ZnO@SiO2 Nanoparticles and Application in Antibiotic and Bacteria Removal, ACS Omega., Vol. 7, 2022, pp. 42073-42082, https://doi.org/10.1021/acsomega.2c04226.
[9] A. K. Srivastava, J. S. Tawale, R. Verma, D. Agarwal, C. Sharma, A. Kumar, M. K. Gupta, Morphological Evolution Driven Semiconducting Nanostructures for Emerging Solar, Biological and Nanogenerator Applications, Mater. Adv., Vol. 3, 2022, pp. 8030-8062, https://doi.org/10.1039/D2MA00683A.
[10] T. L. Phan, S. C. Yu, R. Vincent, H. M. Bui, T. D. Thanh, V. D. Lam, Y. P. Lee, Influence of Mn Doping on Structural, Optical, and Magnetic Properties of Zn1−xMnxO Nanorods, J. Appl. Phys., Vol. 108, 2010, pp. 044910, https://doi.org/10.1063/1.3478709.
[11] A. A. M. Raub, R. Bahru, S. N. A. M. Nashruddin, J. Yunas, A Review on Vertical Aligned Zinc Oxide Nanorods: Synthesis Methods, Properties, and Applications, J. Nanoparticle Res., Vol. 26, 2024, pp. 186, https://doi.org/10.1007/s11051-024-06098-w.
[12] C. C. Lin, Y. Y. Li, Synthesis of ZnO Nanowires by Thermal Decomposition of Zinc Acetate Dihydrate, Mater. Chem. Phys., Vol. 113, 2009, pp. 334-337, https://doi.org/10.1016/j.matchemphys.2008.07.070.
[13] G. L. Mar, P. Y. Timbrell, R. N. Lamb, Formation of Zinc Oxide Thin Films by the Thermal Decomposition of Zinc Zcetate, In: Howe, R. F., Lamb, R. N., Wandelt, K. (eds) Surface Science. Springer Proceedings in Physics, vol 73. Springer, Berlin, Heidelberg, 1993, pp. 177-192, https://doi.org/10.1007/978-3-642-84933-6_15.
[14] R. Saravanan, E. Thirumal, V .K. Gupta, V. Narayanan, A. Stephen, The Photocatalytic Activity of ZnO Prepared by Simple Thermal Decomposition Method at Various Temperatures, J. Mol. Liq., Vol. 177, 2013, pp. 394-401, https://doi.org/10.1016/j.molliq.2012.10.018.
[15] P. Katekaew, A. Prasatkhetragarn, R. Sirirak, C. Boonruang, A. Klinbumrung, Role of the Thermal Regime in the Defect Formation of Zinc Oxide Nanostructures Prepared by the Thermal Decomposition Process, Zeitschrift Für Phys. Chemie., Vol. 237, 2023, pp. 1077-1104, https://doi.org/10.1515/zpch-2023-0235.
[16] S. K. Nikhil, A. Das, M. Kumar P, M. Bhagavathiachari, R.G. Nair, Effect of Aspect Ratio of c-axis Oriented ZnO Nanorods on Photoelectrochemical Performance and Photoconversion Efficiency, Opt. Mater. (Amst)., Vol. 121, 2021, pp. 111551, https://doi.org/10.1016/j.optmat.2021.111551.
[17] A. Das, R. G. Nair, Effect of Aspect Ratio on Photocatalytic Performance of Hexagonal ZnO Nanorods, J. Alloys Compd., Vol. 817, 2020, pp. 153277, https://doi.org/10.1016/j.jallcom.2019.153277.
[18] F. C. Tsao, J. Y. Chen, C. H. Kuo, G. C. Chi, C. J. Pan, P. J. Huang, C. J. Tun, B. J. Pong, T. H. Hsueh, C. Y. Chang, S. J. Pearton, F. Ren, Residual Strain in ZnO Nanowires Grown by Catalyst-free Chemical Vapor Deposition on GaN/Sapphire (0001), Appl. Phys. Lett., Vol. 92, 2008, pp. 203110, https://doi.org/10.1063/1.2936090.
[19] R. Cuscó, E. A. Lladó, J. Ibáñez, L. Artús, J. Jiménez, B. Wang, M. J. Callahan, Temperature Dependence of Raman Scattering in ZnO, Phys. Rev. B., Vol. 75, 2007, pp. 165202, https://doi.org/10.1103/PhysRevB.75.165202.
[20] R. Zhang, P. G. Yin, N. Wang, L. Guo, Photoluminescence and Raman Scattering of ZnO Nanorods, Solid State Sci., Vol. 11, 2009, pp. 865-869, https://doi.org/10.1016/j.solidstatesciences.2008.10.016.
[21] M. Šćepanović, M. G. Brojčin, K. Vojisavljević, S. Bernik, T. Srećković, Raman Study of Structural Disorder in ZnO Nanopowders, J. Raman Spectrosc., Vol. 41, 2010, pp. 914-921, https://doi.org/10.1002/jrs.2546.
[22] V. Russo, M. Ghidelli, P. Gondoni, C. S. Casari, A. L. Bassi, Multi-wavelength Raman Scattering of Nanostructured Al-doped Zinc Oxide, J. Appl. Phys, Vol. 115, 2014, https://doi.org/10.1063/1.4866322.
[23] A. Mondal, S. Pal, A. Sarkar, T. S. Bhattacharya, S. Pal, A. Singha, S. K. Ray, P. Kumar, D. Kanjilal, D. Jana, Raman Investigation of N‐implanted ZnO: Defects, Disorder and Recovery, J. Raman Spectrosc., Vol. 50, 2019, pp. 1926-1937, https://doi.org/10.1002/jrs.5732.
[24] T. L. Phan, T. A. Ho, N. T. Dang, M. C. Nguyen, V. D. Dao, Electronic Structure, Optical and Magnetic Studies of PLD-grown (Mn, P)-doped ZnO Nanocolumns at Room Temperature, J. Phys. D. Appl. Phys., Vol. 50, 2017, pp. 295002, https://doi.org/10.1088/1361-6463/aa75e5.
[25] A. Samavati, A. F. Ismail, H. Nur, Z. Othaman, M. K. Mustafa, Spectral Features and Antibacterial Properties of Cu-doped ZnO Nanoparticles Prepared by Sol-gel Method, Chinese Phys. B., Vol. 25, 2016, pp. 077803, https://doi.org/10.1088/1674-1056/25/7/077803.
[26] N. A. Martynova, S. T. Umedov, L. S. Lepnev, M. Y. Komarova, A. V. Grigorieva, Electrochemicaly Formed ZnO and Au/ZnO Opal Films, SN Appl. Sci., Vol. 2, 2020, https://doi.org/10.1007/s42452-020-2341-z.
[27] P. A. Rodnyi, K. A. Chernenko, I. D. Venevtsev, Mechanisms of ZnO Luminescence in the Visible Spectral Region, Opt. Spectrosc. Vol. 125, 2018, pp. 357-363, https://doi.org/10.1134/S0030400X18090205.
[28] B. Lin, Z. Fu, Y. Jia, Green Luminescent Center in Undoped Zinc Oxide Films Deposited on Silicon Substrates, Appl. Phys. Lett., Vol. 79, 2001, pp. 943-945, https://doi.org/10.1063/1.1394173.
[29] T. E. Murphy, K. Moazzami, J. D. Phillips, Trap-related Photoconductivity in ZnO Epilayers, J. Electron. Mater., Vol. 35, 2006, pp. 543-549, https://doi.org/10.1007/s11664-006-0097-x.
[30] Y. W. Heo, D. P. Norton, S. J. Pearton, Origin of Green Luminescence in ZnO Thin Film grown by Molecular-Beam Epitaxy, J. Appl. Phys., Vol. 98, 2005, https://doi.org/10.1063/1.2064308.
[31] F. Wen, W. Li, J. H. Moon, J. H. Kim, Hydrothermal Synthesis of ZnO:Zn with Green Emission at Low Temperature with Reduction Process, Solid State Commun., Vol. 135, 2005, pp. 34-37, https://doi.org/10.1016/j.ssc.2005.03.066.
[32] I. Musa, N. Qamhieh, S. T. Mahmoud, Synthesis and Length Dependent Photoluminescence Property of Zinc Oxide Nanorods, Results Phys., Vol. 7, 2017, pp. 3552-3556, https://doi.org/10.1016/j.rinp.2017.09.035.
[33] S. Jayswal, R. S. Moirangthem, Thermal Decomposition Route to Synthesize ZnO Nanoparticles for Photocatalytic Application, in, 2018, pp. 020023, https://doi.org/10.1063/1.5052092.
[34] E. Tóthová, M. Senna, A. Yermakov, J. Kováč, E. Dutková, M. Hegedüs, M. Kaňuchová, M. Baláž, Z. L. Bujňáková, J. Briančin, P. Makreski, Zn Source-dependent Magnetic Properties of Undoped ZnO Nanoparticles from Mechanochemically Derived Hydrozincite, J. Alloys Compd., Vol. 787, 2019, pp. 1249-1259, https://doi.org/10.1016/j.jallcom.2019.02.149.
[35] T. L. Phan, Y. D. Zhang, D. S. Yang, N. X. Nghia, T. D. Thanh, S. C. Yu, Defect-induced Ferromagnetism in ZnO Nanoparticles Prepared by Mechanical Milling, Appl. Phys. Lett., Vol. 102, 2013, pp. 072408, https://doi.org/10.1063/1.4793428.
[36] J. M. D. Coey, Ferromagnetism, Solid State Sci., Vol. 7, 2005, pp. 660-667, https://doi.org/10.1016/j.solidstatesciences.2004.11.012.
[37] B. B. Straumal, S. G. Protasova, A. A. Mazilkin, E. Goering, G. Schütz, P. B. Straumal, B. Baretzky, Ferromagnetic Behaviour of ZnO: the Role of Grain Boundaries, Beilstein J. Nanotechnol., Vol. 7, 2016, pp. 1936-1947, https://doi.org/10.3762/bjnano.7.185.
[38] W. Q. Li, J. X. Cao, J. W. Ding, X. Hu, Modulating Magnetism of ZnO:C with Vacancy and Substitution, J. Appl. Phys., Vol. 110, 2011, https://doi.org/10.1063/1.3666051.