Comportamento elétrico e magnético da cerâmica Ni-Zn
Electric and magnetic behavior of Ni-Zn ceramic
Valesca Donizeti de Oliveira, Claudiney de Sales Pereira Mendonça, Manuel Ribeiro da Silva, Rero Marques Rubinger, Adhimar Flávio Oliveira, Vander Alkmin dos Santos Ribeiro
Resumo
As ferritas receberam um renovado interesse tecnológico e científico nos últimos anos, devido ao seu baixo custo de produção e à diversidade de aplicações. As ferritas de níquel-zinco são bem conhecidas como materiais magnéticos moles com boas propriedades, tais como alta resistividade elétrica, baixa perda de corrente parasita em altas frequências e propriedades de aquecimento por indução em um campo magnético alternado (a.c.). Elas são amplamente utilizadas em diversos produtos industriais, como transformadores de potência, micro-ondas e equipamentos de telecomunicações. Amostras de ferritas de níquel-zinco (Nix Zn1-xFe2 O4 , com x = 0,00, 0,25, 0,50, 0,75, 1,00) foram sinterizadas a 1250 °C por 20h usando o método de reação de estado-sólido. A estrutura cúbica de espinélio foi a microestrutura encontrada na série de ferritas Ni-Zn. A estrutura do sistema espinélio misto foi investigada com difração de raios X. As propriedades magnéticas foram caracterizadas com um magnetômetro de amostra vibrante, pelo qual foi obtida a curva de magnetização em função do campo magnético aplicado. A condutividade elétrica DC das pastilhas cilíndricas foi caracterizada com variação da temperatura de 30 °C a 550 °C. Os resultados da caracterização elétrica mostram que as ferritas de níquel-zinco produzidas apresentam características semicondutoras.
Palavras-chave
Abstract
Ferrites have received a renewed technological and scientific interest in recent years, due to their low cost of production and the diversity of applications. Nickel-zinc ferrites are well known as soft magnetic materials with good properties, such as high electrical resistivity, low loss of eddy current at high frequencies and induction heating properties in an alternating magnetic field (a.c.). They are widely used in various industrial products, such as power transformers, microwaves and telecommunications equipment. Samples of nickel-zinc ferrites (Nix Zn1-xFe2 O4 , with x = 0.00, 0.25, 0.50, 0.75, 1.00) were sintered at 1250 °C for 20h using the state reaction method -solid. The spinel cubic structure was the microstructure found in the Ni-Zn ferrite series. The structure of the mixed spinel system was investigated with X-ray diffraction. The magnetic properties were characterized with a vibrating sample magnetometer, by which the magnetization curve was obtained as a function of the applied magnetic field. The DC electrical conductivity of cylindrical pallets was characterized with temperature variation from 30 °C to 550 °C. The results of the electrical characterization show that the nickel-zinc ferrites produced have semiconductor characteristics.
Keywords
Referências
1 Schmalzried H. Chemical kinetics of solids. Verlag Chemie: Weinheim; 1995.
2 Oliveira VD, Rubinger M, Silva MR, Oliveira AF, Rodrigues G, Ribeiro VAS. Magnetic and electrical properties of MnxCu1-xFe2O4 ferrite. Materials Research. 2016;19(4):786-790.
3 Baruwati B, Guin D, Manorama SV. Pd on surface modified NiFe2O4 nanoparticles: a magnetically recoverable catalyst for suzuki and heck reactions. Organic Letters. 2007;9(26):5377-5380.
4 Shultz MD, Calvin S, Fatouros PP, Morrison SA, Carpenter EE. Enhanced ferrite nanoparticles as MRI contrast agents. Journal of Magnetism and Magnetic Materials. 2007;311(1):464-468.
5 Karakaş ZK, Boncukcuoğlu R, Karakaş IH, Ertuğrulc M. The effects of heat treatment on the synthesis of nickel ferrite (nife2o4) nanoparticles using the microwave assisted combustion method. Journal of Magnetism and Magnetic Materials. 2015;374:298- 306.
6 Sato T, Masai A, Ota Y, Sato H, Matuski H, Yanada T, et al. The development of anticancer agent releasing microcapsule made of ferromagnetic amorphous flakes for intratissue hyperthermia. IEEE Transactions on Magnetics. 1993;29:3325-3330.
7 Mansour SF. Frequency and composition dependence on the dielectric properties for Mg-Zn ferrite. Egyptian Journal of Solids. 2005;28(2):263-273.
8 Pu S, Liu M. Tunable photonic crystals based on MnFe2 O4 magnetic fluids by magnetic fields. Journal of Alloys and Compounds. 2009;481:851-854.
9 Hirosawa F, Iwasaki T, Watano S. Synthesis and magnetic induction heating properties of Gd-substituted Mg–Zn ferrite nanoparticles. Applied Nanoscience. 2017;7:209-214.
10 Zhang S, Lee W. Spinel-containing refractories., In: Schacht CA, editor. Refractories handbook. New York: Marcel Dekker; 2004. p. 215.
11 Carta D, Casula MF, Falqui A, Lo Che D, Mountjoy G, Sangregorio C, et al. A structural and magnetic investigation of the inversion degree in ferrite nanocrystals MFe2 O4 (M =Mn, Co, Ni). The Journal of Physical Chemistry C. 2009;113:8606-8615.
12 IHsiang H, Wu JL. Copper-rich phase segregation effects on the magnetic properties and DC-biassuperposition characteristic of NiCuZn ferrites. Journal of Magnetism and Magnetic Materials. 2015;374:367-371.
13 Goldman A. Modern ferrite technology. New York: Springer; 2006.
14 Yahya N, Aripin ASMN, Aziz AA, Daud H, Zaid HM, Pah LK, et al. Synthesis and charaterization of magnesium zinc ferrites as electromagnetic source. American Journal of Engineering and Applied Sciences. 2008;1:53-56.
15 Gabal MA, El-Shishtawy RM, Al Angari YM. Structural and magnetic properties of nano-crystalline ni–zn ferrites synthesized using egg-white precursor. Journal of Magnetism and Magnetic Materials. 2012;324(14):2258-2264.
16 Mancini MW, Paulin Filho PI. Barreiras de potencial mapeadas por microscopia de força atômica em cerâmicas à base de BaTiO3 dopadas com lantânio. Cerâmica. 2007;53:147-152.
17 Montoya ACA. Produção de filmes de Dióxido de titânio para aplicações fotovoltaicas [dissertação] Itajubá: Universidade Federal de Itajubá; 2014.
18 Mardare D, Iftimie N, Crişan M, Răileanu M, Yildiz A, Coman T, et al. Electrical conduction mechanism and gas sensing properties of Pd-doped TiO2 films. Journal of Non-Crystalline Solids. 2011;357(7):1774-1779.
19 Parmar H, Upadhyay RV, Rayaprol S, Siruguri V. Structural and magnetic properties of nickel–zinc ferrite nanocrystalline magnetic particles prepared by microwave combustion method. Indian Journal of Physics. 2014;88:1257-1264.
20 Islam MU, Abbas T, Niazi SB, Ahmed Z, Sabeen S, Chaudhry MA. Electrical behavior of fine particle, Co-precipitation prepared Ni-Zn ferrites. Solid State Communications. 2004;130(5):353-356.
21 Murthy VRK, Sundaram S, Viswanathan B. Microwave materials. Berlim: Springer- Verlag; 1994.
Submetido em:
10/10/2019
Aceito em:
21/07/2021
Facebook
Google+
Twitter
LinkedIn
Mendeley
StumbleUpon
CiteULike
Reddit
Email