Size dependence of the magnetic properties of Ni nanoparticles prepared by thermal decomposition method
© He et al.; licensee Springer. 2013
Received: 13 July 2013
Accepted: 25 September 2013
Published: 28 October 2013
By means of thermal decomposition, we prepared single-phase spherical Ni nanoparticles (23 to 114 nm in diameter) that are face-centered cubic in structure. The magnetic properties of the Ni nanoparticles were experimentally as well as theoretically investigated as a function of particle size. By means of thermogravimetric/differential thermal analysis, the Curie temperature TC of the 23-, 45-, 80-, and 114-nm Ni particles was found to be 335°C, 346°C, 351°C, and 354°C, respectively. Based on the size-and-shape dependence model of cohesive energy, a theoretical model is proposed to explain the size dependence of TC. The measurement of magnetic hysteresis loop reveals that the saturation magnetization MS and remanent magnetization increase and the coercivity decreases monotonously with increasing particle size, indicating a distinct size effect. By adopting a simplified theoretical model, we obtained MS values that are in good agreement with the experimental ones. Furthermore, with increase of surface-to-volume ratio of Ni nanoparticles due to decrease of particle size, there is increase of the percentage of magnetically inactive layer.
The transition metal nickel shows distinct magnetic and catalytic properties [1, 2]. In nanostructure, Ni has great application potential in fields such as pharmaceutical synthesis , magnetic biocatalysis , biomolecular separation , and biosensor . In the literatures, there are reports on the preparation and properties of novel Ni nanomaterials such as sea urchin-like Ni nanoparticles , tetragonal Ni nanoparticles , hexagonal close-packed (hcp) Ni nanoparticles , conical Ni nanorods , triangular and hexagonal Ni nanosheets , and Ni nanochains . It is known that the performance of technological devices is greatly influenced by the purity, structure, shape, and size of Ni nanoparticles. Hence, it is of great significance to prepare high-quality Ni nanomaterials of specificity using convenient and low-cost methods.
For the fabrication of Ni nanoparticles, methods such as sputtering [13, 14], solution glow discharge , pulsed laser ablation , reversed micelles , thermal decomposition [17–20], and wet chemical reduction [7, 21, 22] are used. Among them, the ones based on thermal decomposition are preferred. The single-step process is facile, environment-benign, inexpensive, and reproducible, yielding high-quality Ni powders that can be controlled in terms of structure, morphology, size, and size distribution. It should be pointed out that pure Ni nanoparticles are difficult to prepare because they are easily oxidized. One of the ways to evade the formation of oxide or hydroxide is to carry out the pyrolysis process in organic media. For example, relatively large Ni nanoparticles were prepared through thermal decomposition of Ni(ac)2 4H2O in oleylamine in the presence of 1-adamantane carboxylic acid (ACA) and trioctylphosphine oxide (TOPO) . Furthermore, structure-controlled Ni nanoparticles were prepared via thermal decomposition of Ni(ac)2 4H2O in long-chain amines that acted both as solvent and reducing agent . More interestingly, trigonal Ni nanoparticles were prepared by reacting Ni(COD)2 in tetrahydrofuran with tetra-n-octylammonium carboxylates (as reductant and stabilizer) . Despite the synthesis of superior Ni nanomaterials through the pyrolysis of organometallic salts in organic media has been known for quite some time, the synthesis of Ni nanoparticles 20 to 100 nm in size has only been reported lately.
Bulk Ni exhibits a rock-salt structure and is ferromagnetic (Curie temperature of bulk Ni TCb = 358°C) and electroconductive . In contrast to the bulk counterparts, Ni nanoparticles show magnetic parameters (such as Curie temperature TC, saturation magnetization MS, and coercivity HC) that vary with particle size, usually in a non-linear fashion. Despite the endless number of reports on magnetic studies of Ni nanoparticles [1, 10, 18, 26–30], the influence of particle size on the magnetic properties has not been systematically studied. It is envisaged that the application of Ni nanoparticles can be widened once the intrigue relationship between magnetic properties and particle size of Ni nanomaterials can be delineated.
Herein, we report a facile and reproducible process for large-scale synthesis of face-centered cubic (fcc) Ni nanoparticles (spherical and 23 to 114 nm in diameter). We controlled the size of Ni nanoparticles by regulating the synthesis temperature. We studied the influence of particle size on Curie temperature, saturation magnetization, and coercivity. We establish the size dependence of magnetic properties based on experimental as well as theoretical results, and comment on the critical size of Ni nanoparticles and percentage of magnetically inactive layer.
Size and magnetic parameters for the Ni-particle samples obtained at different temperatures
X-ray diffraction (XRD) patterns of all the samples were obtained by using an X-ray diffractometer (Philips X’pert, Philips, Amsterdam, The Netherlands) with Cu Kα radiation. To examine the morphology and particle sizes, a field-emission scanning electron microscope (SEM) (Hitachi S-4800, Hitachi Ltd., Chiyoda-ku, Japan) was used. High-resolution transmission electron microscope (TEM) image and selected-area electron diffraction (SAED) pattern were obtained from a FEI Tecnai G2-F30 instrument (FEI, Hillsboro, OR, USA) operated at accelerating voltage of 300 kV. In the TEM experiment, the incident electron beam was along the direction perpendicular to the sample. The sample was transferred onto a copper grid by solution dripping with the sample powder under sonication in ethanol. The Curie temperature was measured using a thermogravimetric (TG)/differential thermal analysis (DTA) instrument (Scinco STA-1500, Scinco Co. Ltd., Seoul, South Korea) equipped with a piece of Nd2Fe14B permanent magnet during sample heating (up to 500°C) in argon at a rate of 10°C/min. For comparing, the TG/DTA measurement of a bulk Ni sample (nickel sphere) was conducted under the same conditions. Magnetic measurements were carried out with a vibrating sample magnetometer (VSM) (Lake Shore 7300, Lake Shore Cryotronics, Inc., Westerville, OH, USA). The hysteresis was recorded for powder samples in gelatin capsule, and the hysteresis loops were obtained in a magnetic field up to ±10 kOe. Magnetization versus temperature (M-T) curves were measured in the range 30°C to 400°C using an applied magnetic field of 5 kOe.
Results and discussion
The variation of TC as a function of particle size calculated using Equation (4) is compared with the TG/DTA results. Specifically, the absolute error between the two results has been given by the error bars in Figure 5, and the obtained relative errors are less than 1%. Through this, we can understand that TC decreases with decrease of particle size D, and there is a good match between theoretical and experimental results. In other words, the model represents well the size dependence of the Curie temperature of Ni nanoparticles.
where MSb denotes the saturation magnetization of the corresponding bulk materials, t is the thickness of magnetically inactive layer, and D is the diameter of nanoparticles. Considering our samples of spherical Ni nanoparticles (MSb = 54.4 emu/g) , the percentage of magnetically inactive layer t/D can be calculated using Equation (5). The t/D values for all samples are listed in Table 1. Clearly, as the surface-to-volume ratio of Ni nanoparticles increases with decreasing particle size, the percentage of magnetically inactive layer increases too. In fact, as the particle size reduced from 114 to 23 nm, the t/D value of Ni nanoparticles slightly increases from 2.03% to 4.26%. This slight change suggests that the dead layer theory cannot satisfactorily explain the size dependence of saturation magnetization [39–41].
Substituting the parameters mentioned above into Equation (10), the Dc value of spherical Ni nanoparticles is 0.90 nm. As shown in the final column of Table 1, the percentage of magnetically inactive layer is 4.26%, 3.09%, 2.43%, and 2.03% for spherical Ni nanoparticles with particle sizes of 23, 45, 80, and 114 nm, respectively. Using Equation (5), the corresponding thickness t of magnetically inactive layer is 0.98, 1.39, 1.94, and 2.31 nm for the four Ni-nanoparticle samples. Herein, the critical size (Dc = 0.90 nm) and t values are in the same order of magnitude, but the Dc value is significantly smaller than the four t values. Thus, the size-dependent cohesive energy model under critical condition is consistent with the magnetically dead layer theory.
We systematically studied the size-dependent magnetic properties of spherical Ni nanoparticles in terms of experimental measurement and theoretical calculation. Our results show that the Curie temperature, saturation magnetization, and remanent magnetization increase whereas the coercivity decreases monotonously with the increase of particle size. According to the size-dependent cohesive energy model, a simplified theoretical calculation can be applied to analyze the size dependence of Curie temperature and saturation magnetization. The results of calculation are in good agreement with the experimental results. Under critical condition of critical size Dc = 0.90 nm, the size dependence of magnetization obtained by cohesive energy model is consistent with the analysis of magnetically dead layer theory. With the particle size decreasing, the surface-to-volume ratio of Ni nanoparticles increases and the percentage of magnetically inactive layer increases as well.
The authors greatly acknowledge finical support of the National Natural Science Foundation of China (grant no. 11174132), the National Key Project for Basic Research (grant nos. 2011CB922102 and 2012CB932304), and PAPD, People's Republic of China.
- Feygenson M, Kou A, Kreno LE, Tiano AL, Patete JM, Zhang F, Kim MS, Solovyov V, Wong SS, Aronson MC: Properties of highly crystalline NiO and Ni nanoparticles prepared by high-temperature oxidation and reduction. Phys Rev B 2010, 81: 014420.View ArticleGoogle Scholar
- Baudouin D, Rodemerck U, Krumeich F, de Mallmann A, Szeto KC, Ménard H, Veyre L, Candy JP, Webb PB, Thieuleux C, Copéret C: Particle size effect in the low temperature reforming of methane by carbon dioxide on silica-supported Ni nanoparticles. J Catal 2013, 297: 27–34.View ArticleGoogle Scholar
- Khurana JM, Yadav S: Highly monodispersed PEG-stabilized Ni nanoparticles: proficient catalyst for the synthesis of biologically important spiropyrans. Aust J Chem 2012, 65: 314–319. 10.1071/CH11444View ArticleGoogle Scholar
- Bussamara R, Eberhardt D, Feil AF, Migowski P, Wender H, de Moraes DP, Machado G, Papaléo RM, Teixeira SR, Dupont J: Sputtering deposition of magnetic Ni nanoparticles directly onto an enzyme surface: a novel method to obtain a magnetic biocatalyst. Chem Commun 2013, 49: 1273–1275. 10.1039/c2cc38737aView ArticleGoogle Scholar
- Lee KB, Park S, Mirkin CA: Multicomponent magnetic nanorods for biomolecular separations. Angew Chem Int Ed 2004, 43: 3048–3050. 10.1002/anie.200454088View ArticleGoogle Scholar
- Kalita P, Singh J, Singh MK, Solanki PR, Sumana G, Malhotra BD: Ring like self assembled Ni nanoparticles based biosensor for food toxin detection. Appl Phys Lett 2012, 100: 093702. 10.1063/1.3690044View ArticleGoogle Scholar
- Ma F, Huang JJ, Li JG, Li Q: Microwave properties of sea-urchin-like Ni nanoparticles. J Nanosci Nanotechnol 2009, 9: 3219–3223. 10.1166/jnn.2009.051View ArticleGoogle Scholar
- Roy A, Srinivas V, Ram S, Chandrasekhar-Rao TV: The effect of silver coating on magnetic properties of oxygen-stabilized tetragonal Ni nanoparticles prepared by chemical reduction. J Phys Condens Matter 2007, 19: 346220. 10.1088/0953-8984/19/34/346220View ArticleGoogle Scholar
- García-Cerda LA, Bernal-Ramos KM, Montemayor SM, Quevedo-López MA, Betancourt-Galindo R, Bueno-Báques D: Preparation of hcp and fcc Ni and Ni/NiO nanoparticles using a citric acid assisted pechini-type method. J Nanomater 2011. doi: 10.1155/2011/162495 doi: 10.1155/2011/162495Google Scholar
- Ma F, Ma J, Huang JJ, Li JG: The shape dependence of magnetic and microwave properties for Ni nanoparticles. J Magn Magn Mater 2012, 324: 205–209. 10.1016/j.jmmm.2011.08.013View ArticleGoogle Scholar
- Leng YH, Wang YT, Li XG, Liu T, Takahashhi S: Controlled synthesis of triangular and hexagonal Ni nanosheets and their size-dependent properties. Nanotechnology 2006, 17: 4834–4839. 10.1088/0957-4484/17/19/009View ArticleGoogle Scholar
- Chen WM, Zhou W, He L, Chen CP, Guo L: Surface magnetic states of Ni nanochains modified by using different organic surfactants. J Phys Condens Matter 2010, 22: 126003. 10.1088/0953-8984/22/12/126003View ArticleGoogle Scholar
- Akamaru S, Inoue M, Honda Y, Taguchi A, Abe T: Preparation of Ni nanoparticles on submicron-sized Al2O3 powdery substrate by polyhedral-barrel-sputtering technique and their magnetic properties. Jpn J Appl Phys 2012, 51: 065201.Google Scholar
- Maicas M, Sanz M, Cui H, Aroca C, Sánchez P: Magnetic properties and morphology of Ni nanoparticles synthesized in gas phase. J Magn Magn Mater 2010, 322: 3485–3489. 10.1016/j.jmmm.2010.06.050View ArticleGoogle Scholar
- Saito G, Hosokai S, Akiyama T, Yoshida S, Yatsu S, Watanabe S: Size-controlled Ni nanoparticles formation by solution glow discharge. J Phys Soc Jpn 2010, 79: 083501. 10.1143/JPSJ.79.083501View ArticleGoogle Scholar
- Calandra P: Synthesis of Ni nanoparticles by reduction of NiCl2 ionic clusters in the confined space of AOT reversed micelles. Mater Lett 2009, 63: 2416–2418. 10.1016/j.matlet.2009.08.016View ArticleGoogle Scholar
- Gonzalez I, De-Jesus JC, Cañizales E, Delgado B, Urbina C: Comparison of the surface state of Ni nanoparticles used for methane catalytic decomposition. J Phys Chem C 2012, 116: 21577–21587. 10.1021/jp302372rView ArticleGoogle Scholar
- Choo S, Lee K, Jo Y, Yoon SM, Choi JY, Kim JY, Park JH, Lee KJ, Lee JH, Jung MH: Interface effect of magnetic properties in Ni nanoparticles with a hcp core and fcc shell structure. J Nanosci Nanotechnol 2011, 11: 6126–6130. 10.1166/jnn.2011.4488View ArticleGoogle Scholar
- Kotoulas A, Gjoka M, Simeonidis K, Tsiaoussis I, Angelakeris M, Kalogirou O, Dendrinou-Samara C: The role of synthetic parameters in the magnetic behavior of relative large hcp Ni nanoparticles. J Nanopart Res 2011, 13: 1897–1908. 10.1007/s11051-010-9941-2View ArticleGoogle Scholar
- Carroll KJ, Ulises-Reveles J, Shultz MD, Khanna SN, Carpenter EE: Preparation of elemental Cu and Ni nanoparticles by the polyol method: an experimental and theoretical approach. J Phys Chem C 2011, 115: 2656–2664. 10.1021/jp1104196View ArticleGoogle Scholar
- Bala T, Gunning RD, Venkatesan M, Godsell JF, Roy S, Ryan KM: Block copolymer mediated stabilization of sub-5 nm superparamagnetic nickel nanoparticles in an aqueous medium. Nanotechnology 2009, 20: 415603. 10.1088/0957-4484/20/41/415603View ArticleGoogle Scholar
- Yamauchi Y, Itagaki T, Yokoshima T, Kuroda K: Preparation of Ni nanoparticles between montmorillonite layers utilizing dimethylaminoborane as reducing agent. Dalton Trans 2012, 41: 1210–1215. 10.1039/c1dt11395jView ArticleGoogle Scholar
- Mourdikoudis S, Simeonidis K, Vilalta-Clemente A, Tuna F, Tsiaoussis I, Angelakeris M, Dendrinou-Samara C, Kalogirou O: Controlling the crystal structure of Ni nanoparticles by the use of alkylamines. J Magn Magn Mater 2009, 321: 2723–2728. 10.1016/j.jmmm.2009.03.076View ArticleGoogle Scholar
- Bradley JS, Tesche B, Busser W, Maase M, Reetz MT: Surface spectroscopic study of the stabilization mechanism for shape-selectively synthesized nanostructured transition metal colloids. J Am Chem Soc 2000, 122: 4631–4636. 10.1021/ja992409yView ArticleGoogle Scholar
- Cullity BD, Graham CD: Introduction to Magnetic Materials. Piscataway: IEEE Press; 2009.Google Scholar
- Gong W, Li H, Zhao ZR, Chen JC: Ultrafine particles of Fe, Co, and Ni ferromagnetic metals. J Appl Phys 1991, 69: 5119–5121. 10.1063/1.348144View ArticleGoogle Scholar
- Tzitzios V, Basina G, Gjoka M, Alexandrakis V, Georgakilas V, Niarchos D, Boukos N, Petridis D: Chemical synthesis and characterization of hcp Ni nanoparticles. Nanotechnology 2006, 17: 3750–3755. 10.1088/0957-4484/17/15/023View ArticleGoogle Scholar
- Singh V, Srinivas V, Ram S: Structural and magnetic properties of polymer-stabilized tetragonal Ni nanoparticles. Philos Mag 2010, 90: 1401–1414. 10.1080/14786430903382836View ArticleGoogle Scholar
- Leontyev V: Magnetic properties of Ni and Ni-Cu nanoparticles. Phys Stat Sol (b) 2013, 250: 103–107. 10.1002/pssb.201248152View ArticleGoogle Scholar
- Peng TC, Xiao XH, Wu W, Fan LX, Zhou XD, Ren F, Jiang CZ: Size control and magnetic properties of single layer monodisperse Ni nanoparticles prepared by magnetron sputtering. J Mater Sci 2012, 47: 508–513. 10.1007/s10853-011-5827-7View ArticleGoogle Scholar
- He T, Chen DR, Jiao XL: Controlled synthesis of Co3O4 nanoparticles through oriented aggregation. Chem Mater 2004, 16: 737–743. 10.1021/cm0303033View ArticleGoogle Scholar
- Morrish AH: The Physical Principles of Magnetism. Piscataway: IEEE Press; 2001.View ArticleGoogle Scholar
- Xie D, Wang MP, Cao LF: A simplified model to calculate the higher surface energy of free-standing nanocrystals. Phys Stat Sol (b) 2005, 242: R76-R78. 10.1002/pssb.200510036View ArticleGoogle Scholar
- Rytkönen A, Valkealahti S, Manninen M: Melting and evaporation of argon clusters. J Chem Phys 1997, 106: 1888–1892. 10.1063/1.473327View ArticleGoogle Scholar
- Askeland DR, Phule PP: The Science and Engineering of Materials. New York: Thomson Learning Inc; 2003.Google Scholar
- : Web elements periodic table. . Accessed 25 March 2013 http://www.webelements.com/nickel/ . Accessed 25 March 2013
- Shafi KVPM, Gedanken A, Prozorov R, Balogh J: Sonochemical preparation and size-dependent properties of nanostructured CoFe2O4 particles. Chem Mater 1998, 10: 3445–3450. 10.1021/cm980182kView ArticleGoogle Scholar
- Sharifi I, Shokrollahi H, Amiri S: Ferrite-based magnetic nanofluids used in hyperthermia applications. J Magn Magn Mater 2012, 324: 903–915. 10.1016/j.jmmm.2011.10.017View ArticleGoogle Scholar
- Kodama RH: Magnetic nanoparticles. J Magn Magn Mater 1999, 200: 359–372. 10.1016/S0304-8853(99)00347-9View ArticleGoogle Scholar
- Tang ZX, Sorensen CM, Klabunde KJ, Hadjipanayis GC: Size-dependent Curie temperature in nanoscale MnFe2O4 particles. Phys Rev Lett 1991, 67: 3602–3605. 10.1103/PhysRevLett.67.3602View ArticleGoogle Scholar
- Yamada O, Ono F, Nakai I, Maruyama H, Ohta K, Suzuki M: Comparison of magnetic properties of Fe-Pt and Fe-Pd invar alloys with those of Fe-Ni invar alloys. J Magn Magn Mater 1983, 31–34(1):105–106.View ArticleGoogle Scholar
- Yang CC, Jiang Q: Size and interface effects on critical temperatures of ferromagnetic, ferroelectric and superconductive nanocrystals. Acta Mater 2005, 53: 3305–3311. 10.1016/j.actamat.2005.03.039View ArticleGoogle Scholar
- Sun CQ, Zhong WH, Li S, Tay BK, Bai HL, Jiang EY: Coordination imperfection suppressed phase stability of ferromagnetic, ferroelectric, and superconductive nanosolids. J Phys Chem B 2004, 108: 1080–1084. 10.1021/jp0372946View ArticleGoogle Scholar
- Zhong WH, Sun CQ, Li S: Size effect on the magnetism of nanocrystalline Ni films at ambient temperature. Solid State Commun 2004, 130: 603–606. 10.1016/j.ssc.2004.03.025View ArticleGoogle Scholar
- Zhong WH, Sun CQ, Li S, Bai HL, Jiang EY: Impact of bond-order loss on surface and nanosolid magnetism. Acta Mater 2005, 53: 3207–3214. 10.1016/j.actamat.2005.03.025View ArticleGoogle Scholar
- Jiang Q, Zhao DS, Zhao M: Size-dependent interface energy and related interface stress. Acta Mater 2001, 49: 3143–3147. 10.1016/S1359-6454(01)00232-4View ArticleGoogle Scholar
- Jiang Q, Li JC, Chi BQ: Size-dependent cohesive energy of nanocrystals. Chem Phys Lett 2002, 366: 551–554. 10.1016/S0009-2614(02)01641-XView ArticleGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.