Main results |
- Successfully fabricated some single-phase compounds of BaTiO3, La1,5Sr0,5NiO4, La0,7Sr0,3MnO3, NiFe2O4, CoFe2O4 and some composites xNiFe2O4/(1-x)BaTiO3, xCoFe2O4/(1-x)BaTiO3, xLa1,5Sr0,5NiO4/(1-x)BaTiO3 in nanotructures. The particle sizes of the samples were quite uniform and distributed in the range of 30-70 nm. - The magnetic and electrical properties at room temperature of above compounds have been investigated and pointed out that: BaTiO3 is a ferroelectric; La0,7Sr0,3MnO3, NiFe2O4, and CoFe2O4 are ferromagnetic materials; La1,5Sr0,5NiO4 is a dielectric material; BiFeO3, xNiFe2O4/(1-x)BaTiO3, xCoFe2O4/(1-x)BaTiO3, and xLa1,5Sr0,5NiO4/(1-x)BaTiO3 are multiferroics. - Fabricated absorbing paint and absorbent sheets coated on mica and mica/Al substrates using 0,2La1,5Sr0,5NiO4-0,8BaTiO3 and 0,3NiFe2O4-0,7BaTiO3 multiferroics dispersed in acrylic paint with the wt. ratio of 1/2 and 3/7. The area of absorbing layers is 10x10 cm2 with various thicknesses in a range of 2-6 mm. In which, the absorbing layer with a thickness of 6.0 mm including 24 layers of 3[0.3NiFe2O4-0.7BaTiO3]/7acrylic exhibits the best absorption capacity, the maximum absorption is over 99.99% and over 99.999% at the resonant frequencies of 5.52 GHz and 9.78 GHz, respectively. - Studying the electromagnetic wave absorption properties of the fabricated samples and showing the absorption mechanism of the materials, in which the dielectric loss due to the La1.5Sr0.5NiO4 and BaTiO3 phases and magnetic loss due to the ferromagnetic resonance of the NiFe2O4 phase play the decisive roles. The electromagnetic loss has be controled via the ratio of the dielectric/ferromagnetic and/or ferroelectric/ferromagnetic phases in the multiferroic nanocomposites. The electromagnetic energy of the incident wave is absorbed to the maximum when this ratio reaches the optimal value (0.2La1.5Sr0.5NiO4-0.8BaTiO3 and 0.3NiFe2O4-0.7BaTiO3). - Expanding the research object: studied on the absorbing electromagnetic wave properties of SrFe12-2xCux/2Cox/2TixO19. They have good ability to absorb electromagnetic waves (with t = 0.75 mm, RL < -30 dB corresponding to Amax > 99.9% at resonant frequency) and have the a large effective absorption bandwidth (EAB = 8.8-10.27 GHz). |
Products of the project | - Scientific papers in referred journals (list): 06 papers [1]. T D Thanh, C T A Xuan, T N Bach, B X Khuyen, D S Lam, D C Linh, L T Giang, V D Lam, “Magnetic and microwave absorbing properties of La0.7Sr0.3MnO3 nanoparticles”, AIP Adv. 12 (2022) 035134. [2]. P T Tho, C T A Xuan, N Tran, N Q Tuan, W H Jeong, S W Kim, T Q Dat, V D Nguyen, T N Bach, T D Thanh, D T Khan, B W Lee, “Ultra-wide effective absorption bandwidth of Cu, Co, and Ti co-doped SrFe12O19 hexaferrite”, Ceram. Int. 48 (2022) 27409. [3]. T D Thanh, D S Lam, D C Linh, B X Khuyen, D H Manh, D D Dung, N T Dung, C T A Xuan, N Tran “Multiferroic characteristics and microwave absorption properties of La1.5Sr0.5NiO4/BaTiO3 nanocomposites”, Adv. Nat. Sci.: Nanosci. Nanotechnol. 13 (2022) 045002. [4]. D C Linh, D S Lam, N T V Chinh, D D Dung, N Tran, T D Thanh, “Enhanced ferroelectric and ferromagnetic properties of xNiFe2O4/(1–x)Ba0.94Ca0.06Ti0.975Zr0.025O3 nanocomposites”, Adv. Nat. Sci.: Nanosci. Nanotechnol. (Accepted 28/01/2023). [5]. D S Lam, D C Linh, H T Anh, D D Dung, D H Manh, N H Dan, T D Thanh, “Multiferroic (NiZn)Fe2O4-BaTiO3 composites prepared by high energy ball milling and thermal processing methods”, Proceedings of The 10th International Workshop on Advanced Materials Science and Nanotechnology (IWAMSN 2021), November 4-6, 2021 Hanoi, Vietnam (2021) 398. [6]. Đ S Lâm, N T Dung, Đ Đ Dũng, T Đ Thành, “Tính chất quang, điện và từ của vật liệu nano tổ hợp đa pha điện từ NiFe2O4-BaTiO3” Proceedings of The Advances in Optics, Photonics, Spectroscopy & Applications XI, (2021) 420. - Technological products (describe in details: technical characteristics, place): + 01 manufacturing process for radar-absorbing paint using multiferroic nanocomposites as filler and acrylic as carrier. + 01 litre absorbing paint using multiferroic nanocomposites as filler and acrylic as carrier. + 02 absorbing samples coated on mica and mica/Al with area ≥ 100 cm2, using on a Vector Network Analyzer. Storage place: Laboratory of Magnetism and Superconductivity, Institute of Materials Science. |