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Home Search Collections Journals About Contact us My IOPscience Temperature-time induced changes in magnetic properties of multi-component Fe78Si3.6C13.4Mn0.65B4.35 alloy This content has been downloaded from IOPscience Please scroll down to see the full text 2016 J Phys.: Conf Ser 755 012025 (http://iopscience.iop.org/1742-6596/755/1/012025) View the table of contents for this issue, or go to the journal homepage for more Download details: IP Address: 80.82.77.83 This content was downloaded on 08/03/2017 at 12:54 Please note that terms and conditions apply You may also be interested in: Optimal Temperature-Time Condition for the Post-Exposure Bake Process of Deep-UV Resists Tsung-Lung Li and Jyh-Hua Ting Time Dependence of the Reaction-Diffusion Simulation of the Postexposure Bake Process Deep-Ultraviolet Resists Tsung-Lung Li and Jyh-Hua Ting of Reexaminations of the effects of magnetic field on the nucleation of undercooled Cu melt Jun Wang, Yixuan He, Jinshan Li et al Micro-apparatus for temperature-time curves, and a high-temperature thermostat W E L Brown High-temperature superconduction in bismuth cuprate film R P Gupta, W S Khokle, C C Tripathi et al Development of control method for ferrite phase composition using thermomagnetometric analysis A L Astafyev, E N Lysenko, A P Surzhikov et al A heating rate controller for accelerated storage tests (for chemical products) A W Barendsz, C H Mooij and M A Werner A calorimeter for measuring liquid evaporation rates C A Reading and A Reiser A heating-rate controller for thermoluminescence studies K Inabe International Conference on Recent Trends in Physics 2016 (ICRTP2016) IOP Publishing Journal of Physics: Conference Series 755 (2016) 012025 doi:10.1088/1742-6596/755/1/012025 Temperature-time induced changes in magnetic properties of multi-component Fe78Si3.6C13.4Mn0.65B4.35 alloy S N Kanea, S S Modakb, M Shaha, M Satalkara, K Gehlota, N Ghodkec, J P Araujod and L K Vargae a Magnetic Materials Laboratory, School of Physics, Devi Ahilya University, Khandwa Road Campus, Indore-452001, India b Department of Physics, Jaypee University of Engineering and Technology, Guna-473226, India c UGC-DAE-CSR, University campus, Khandwa Road, Indore-452001, India d IFIMUP, Departmento de Fisica, Universidade de Porto, 4169-007 Porto, Portugal e RISSPO, Hungarian Academy of Sciences, P.O Box, 49-125 Budapest, Hungary Corresponding author: kane_sn@yahoo.com Abstract Influence of thermal annealing as a function of temperature and time, on magnetic and structural properties of Fe78Si3.6C13.4Mn0.65B4.35 (Fe78Si3.6C13.4Mn0.65 = Ci) alloy has been reported Information on structure, formed nano-crystalline phases and their correlation with magnetic properties has been studied using, magnetic measurements, differential scanning calorimetery (DSC) and x-ray diffraction (XRD) Thermal annealing treatment leads to rather coarse grain microstructure (~31 nm) accompanied by surface crystallization that appears to deteriorate the magnetic properties with annealing temperature Introduction Fabrication of Fe-based bulk metallic glasses using high purity raw elements and the strict processing under high vacuum results in high production cost That eventually restricts their industrial mass production In this respect cast iron (Ci) based multi component bulk-type Fe-based amorphous alloys emerged as suitable cheap magnetic alloys prepared with industrially available raw materials [1, 2] These alloys exhibit large glass forming region and good soft magnetic properties Depending upon the specific application requirement these cast iron based alloys can be prepared in the shape of ribbons, cylinders with transversal dimensions up to ~ 0.5 mm [3] and, their magnetic properties should also be optimized In the present work we report the investigation of the effect of isochronal and isothermal annealing treatment on the structural and magnetic properties of cast iron based multi component Fe78Si3.6C13.4Mn0.65B4.35 which is also represented as Ci 95.65B4.35 alloy Experimental Details Ribbons (about 16 m thick and 3.3 mm wide) of nominal composition Fe78Si3.6C13.4Mn0.65B4.35 were prepared using planar flow casting technique In order to determine the crystallization peak temperature differential scanning calirimetery (DSC) measurements were done at heating rate of 10 Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI Published under licence by IOP Publishing Ltd International Conference on Recent Trends in Physics 2016 (ICRTP2016) IOP Publishing Journal of Physics: Conference Series 755 (2016) 012025 doi:10.1088/1742-6596/755/1/012025 o C/min Utilizing DSC results, isochronal thermal annealing was done at 350, 380, 400, 425 and 450 C for 60 minutes Samples were also isothermally annealed at 380 0C for 15, 30 and 45 minutes Xray diffraction (XRD) measurements on as-cast and annealed samples were carried out using Bruker D8 Advance X-ray diffractometer with Cu-K radiation (wavelength: = 0.154 nm) XRD patterns were analyzed by fitting a crystalline and an amorphous component using pseudo-Voigt line profiles Crystalline volume fraction (Vx) was obtained by integrating the main diffraction peak The average grain size D is obtained by Scherrer’s formula using integral width of the (110) line and the lattice parameter a is calculated using Nelson-Taylor-Sinclair correction in order to take into account the peak shift due to sample offset For the amorphous phase, the first nearest neighbour distance Xm is calculated using the expression: Xm = 1.227 / 2Sin Hysteresis loops of as cast and annealed samples were measured using a loop tracer at 50Hz using maximum applied magnetic field of ± 3000 A/m Measured hysteresis loops were used to get information on coercive field (Hc) and, saturation induction (B3000) values o Results and Discussion Figure depicts the DSC curve of as cast sample measured at 10 oC/min It can be seen that the studied alloy system exhibit a two step crystallization process with onset of the first peak at 4350C The crystallization temperatures corresponding to the two peaks are 463 and 524 oC respectively XRD patterns of as cast and annealed samples at various temperatures for 60 are presented in figure Perusal of figure shows that the crystallization starts after annealing at 380 oC X-ray diffraction data was analyzed using a MATLAB based program that fits the data using pseudo Voigt line profiles Table represents the annealing temperature evolution of various structural parameters obtained by analyzing the XRD data Effect of isothermal annealing at 380 oC for different time period on the structural properties of the studied alloy samples is shown in table Perusal of tables and shows that with increasing annealing temperature, although D increases but Vx does not increase much, exhibiting that increase in annealing temperature results in grain coarsening Change of annealing time does not have appreciable effect on, D and Vx Obtained a values suggest that the precipitated crystalline phase is bcc Fe (–Fe) Within the experimental errors the first nearest-neighbour distance in the residual amorphous matrix (0.250 nm 0.001) almost remains constant for the studied specimens, showing that the studied samples have comparable mass densities Effect of annealing temperature and time on the magnetic response of the studied alloy composition is represented in the figure Perusal of figure (left panel) indicates that the flattening of hysteresis loops occur for the annealing temperature of 400 oC and above as also observed in case of other cast iron based samples ascribable to surface crystallization [4,5] Heat flow (a.u) As-cast 300 Ann 350 oC/1h Exo Intensity (A.U.) Ann 380 oC/1h Ann 400 oC/1h Ann 425 oC/1h Ann 450 oC/1h 400 500 Temperature (oC) 600 30 40 50 60 70 80 90 (Degrees) Figure 2: XRD patterns of as cast and annealed Fe78Si3.6C13.4Mn0.65B4.35 samples at various temperatures for 60 minutes Figure 1: DSC curve of as cast Fe78Si3.6C13.4Mn0.65B4.35 sample measured at 10 oC/minute International Conference on Recent Trends in Physics 2016 (ICRTP2016) IOP Publishing Journal of Physics: Conference Series 755 (2016) 012025 doi:10.1088/1742-6596/755/1/012025 Table1: Temperature transformation of structural parameters for samples annealed for 60 minutes Sample details Table2: Time transformation of structural parameters for samples annealed at 380 oC (nm) a (nm) Vx (%) (1) ( 0001) (1) As-cast 380 oC 11.5 0.2849 5.5 400 oC 17.5 0.2848 10.5 425 oC 25 0.2849 19 31.5 0.2848 30.5 o 450 C (nm) a (nm) Vx (%) (1) (0.0001) (1) As-cast 15 11.0 0.2868 3.2 30 11.0 0.2869 3.9 45 11.5 0.2845 6.0 60 11.5 0.2849 5.5 Sample details As-q 1.5 350 oC 1.0 380 oC 400 oC 0.5 425 oC 0.0 -0.5 -1.0 -1.5 -200 -100 1.5 15 1.0 30 45 0.5 60 0.0 -0.5 -1.0 -1.5 -200 -100 B (Tesla) B (Tesla) In order to further optimize the magnetic properties of the studied alloy system, the annealing temperature of 380 oC was chosen, which shows partial crystallization with average grain diameter of 11 nm It is worth noting that XRD pattern of the specimen annealed at 380 oC, shows presence of small crystalline fraction ( %) after annealing for hour By choosing different annealing time would lead to various levels of structural relaxation and/or crystallization having different average grain diameter of the nano-grains, giving rise to the variation in magnetic properties Keeping the above mentioned reason in account, specimens were also annealed at 380 oC for different times e.g 15, 30, 45 and 60 Time evolution of the hysteresis loops corresponding to annealing temperature of 380 oC is presented in figure (right panel) Figure represents the annealing temperature and time evolution of coercive field behaviour of the studied samples It shold be noted that insets in the figure (both in left and right panel) exhibit the variation of saturation induction (B3000) values as a function of isochronal and isothermal annealing treatment respectively It can be seen in the figure (left panel) that there is an initial decrement in the coercvity till annealing temperature of 350 oC, which may be due to relaxation of quenched in stresses Further coercive field values increases rather sharply with annealing temperature 100 H (A/m) 200 100 H (A/m) 200 Figure 3: Annealing temperature evolution of representative hysteresis curves of Fe78Si3.6C13.4Mn0.65B4.35 alloy (left panel) Annealing time evolution of Fe78Si3.6C13.4Mn0.65B4.35 alloy samples annealed at 380 oC (right panel) International Conference on Recent Trends in Physics 2016 (ICRTP2016) IOP Publishing Journal of Physics: Conference Series 755 (2016) 012025 doi:10.1088/1742-6596/755/1/012025 Ci95.65B4.35 12 1.4 100 1.3 1.2 100 200 300 o 400 500 Ann Temp ( C) 10 1.40 1.35 1.30 1.25 15 100 200 300 o 400 500 Ann Temp ( C) Ci95.65B4.35 1.45 10 1.1 1.50 B3000 (Tesla) 1.5 Coercivity (A/m) 1.6 B3000 (Tesla) Coercivity (A/m) 1000 15 30 45 Ann Time (Min.) 30 45 Ann Time (Min.) 60 60 Figure 4: Annealing temperature evolution of coercivity and saturation induction values (inset) of Fe78Si3.6C13.4Mn0.65B4.35 alloy (left panel) Annealing time evolution of coercivity and saturation induction (inset) of Fe78Si3.6C13.4Mn0.65B4.35 alloy samples annealed at 380 oC (right panel) This behaviour indicates the presence of non-exchange coupled nanograins It can be seen in table that grain coarsening (average grain diameter~31 nm and Vx ~ 30%) is responsible for large distance between the grains and hence deteriorating the magnetic properties Coercive field values of the studied alloy system varies between to 914 A/m The lowest value of coercivity (Hc ~ A/m) is exhibited for the sample annealed at 3800C for 15 It should also be noted that the saturation induction (B3000) values ranges between 1.28 to 1.54 Tesla Highest value (1.54 T) of B3000 corresponds to the annealing treatment at the temperature of 400 oC for 60 Summary Changes in the structural and magnetic properties as a function of thermal annealing temperature and time for cast iron based multi component Fe78Si3.6C13.4Mn0.65B4.35 alloy in the form of ribbons have been studied using DSC, XRD and hysteresis measurements Studied alloy system exhibit two-step crystallization, exhibiting a pre-peak, before the main peak For the samples isochronally annealed at various temperatures, coercive field values range between – 914 A/m,whereas B3000 values vary between 1.28 - 1.54 Tesla The lowest Hc value of A/m was obtained for the sample annealed at 380 o C for 15 Best B3000 value of 1.54 Tesla was obtained for the one annealed at 400 oC for hr Obtained lattice parameter values suggest that the precipitated crystalline phase is bcc Fe (–Fe) Thermal annealing leads to rather coarse grains ~ 31 nm, but low crystalline fraction ~ 30% This appears to reduce the ferromagnetic exchange interaction between –Fe nano-crystals, thereby deteriorating the magnetic properties Thermal annealing leads to the flattening of the hysteresis loop that ascribed to surface crystallization Acknowledgement S N Kane acknowledges gratefully the financial support from Indo Portuguese joint project No.IND/Portugal/P-07/2013 and, also by the project CSR-IC-IC-BL-25/CRS-122-2014-15/218 References [1] Inoue A, Shen B L, Koshiba H, Kato H and Yavari A R 2004 Acta Mater 52 1631 [2] Qin C, Zhang W, Asami K, Ohtsu N and Inoue A 2005 Acta Mater 53 3903 [3] Inoue A and Wang X M 2000 Acta Mater 48 1383 [4] Kane S N, Lee H J, Kim S B, Jeong Y H, Hyun S W, Kim C S and Varga L K 2009 J Physics: Conference series 144 012040 [5] Herzer G and Hilzinger H R 1986 J Magn Magn Mater 62 143 ... Abstract Influence of thermal annealing as a function of temperature and time, on magnetic and structural properties of Fe78Si3. 6C13. 4Mn0. 65B4. 35 (Fe78Si3. 6C13. 4Mn0. 65 = Ci) alloy has been reported Information... representative hysteresis curves of Fe78Si3. 6C13. 4Mn0. 65B4. 35 alloy (left panel) Annealing time evolution of Fe78Si3. 6C13. 4Mn0. 65B4. 35 alloy samples annealed at 380 oC (right panel) International Conference... Ann Time (Min.) 60 60 Figure 4: Annealing temperature evolution of coercivity and saturation induction values (inset) of Fe78Si3. 6C13. 4Mn0. 65B4. 35 alloy (left panel) Annealing time evolution of