For understanding the behavior of different elements the micro magnetic modeling is used. There are two types of simulators. Among them one is OOMMF method. OOMMF method is developed by microphone Donahue. The values of OOMMF are observed in both two-dimensional and three-dimensional field. But in this job merely two-dimensional is used because in convenient harmonizing to length in nanometres and for understanding the magnetic constellation of nanoelements.In below we had given a brief item about Fe and permalloy.we have mentioned about the working rule of OOMMF method and we have besides given a item about the samples taken. The consequences obtained are showed below for different way geometry.
1.1 ) Iron: Iron is a metallic component that can be rust in air and combines with some pyrogenic stones and biologically it is used in human organic structure for transporting the O inside the organic structure. Iron is denoted as ‘Fe’.It is the 10th abundant component in the existence. This component is discovered by Egyptians in 4000Bc and it is derived from Latin word ‘Ferrum’.In the periodic tabular array Fe is located in groups 3-12.Atomic figure of Fe is 26 and the mass can be up to 7.86g/cm3. Iron is used in human organic structure as haemoglobin molecule. Iron is less expensive, easy available metal in universe so among all elements it is utile metal. In universe Fe is an abundant component because in Sun and in many of stars it is available. In the Earth ‘s crust Fe is a most available metal about 4th topographic point. The of import Fe ore is hematite it is obtained by decrease of C from the metal Fe. In Fe spheres are formed due to the magnetisation energy and these spheres will be closing and Fe can stipulate now to hold the sphere construction. Iron can organize two, three or four spheres depending upon the length of the stuff. In each sphere there will be vertices indicate due to this point all spheres are in equal distance. The chief belongings of Fe is crystalline anisotropy alterations due to magnetization in it. Anisotropy in Fe is to be cubelike sometimes due to the applied field on it. If more spheres are formed in Fe ore means the demagnetization energy field will be reduced. The magnetisation occurs in Fe in all waies. Shape anisotropy of Iron metal would be low.
1.2 ) Permalloy: Permalloy is an component formed by blend of approximately 80 % Nickel and 20 % and has high magnetic permeableness. Depending upon the way of applied magnetic field and strength of the component the electrical electric resistance varies. Chiefly Permalloy is used to wrap around the Cu wires that used in tele-communication intent and besides used in entering detectors and besides in transformer laminations. It is besides used in production of electrical transformers and inductances. In 1940 the bell research lab has invented this Permalloy component by heat intervention and proposed it has more permeableness than Si. Molybdenum Permalloy is the composing of Permalloy. Permalloy have no anisotropy energy but it dependent on both exchange and demagnetisation energy. As similar in Fe as Bloch walls appears here Neel walls can be formed. Permalloy is obtained in assorted signifiers like Permalloy thin films.Permalloy is used as Ac transformers and sensitive relays because it has big impregnation initiation. If there is alteration in electrical opposition so it leads to structural transmutations when condensates are interfered. In Permalloy the resonance frequence and permeableness depends up on the length of the stuff. When Permalloy is heated and if it consists of 5 % of Mo in H component so supermalloy besides will hold high permeableness.
1.3 ) OOMMF Model: OOMMF means object oriented micro magnet frame work. Basically micro magnetic modeling is used for detecting different belongingss of materials.OOMMF is a functional micro magnetic codification. This is a flexible plan because every person can make their ain codification. When a new codification is written for this oommf by user so this new codification can be replace with old codification by single itself that means easy the old codification can be swiped with new codification. The major end of OOMMF is to develop portable package so that can any user can travel it from one topographic point to another topographic point and this package must be used freely by any user. The purpose is besides to supply a micro modeling plan with association tools.
The OOMMF is launched by snaping icon on screen so it opens from millimeter launch 18.104.22.168 window and it consists of millimeter Archive, millimeter graph, millimeter datatable, mm Disp, millimeter probed and millimeter solve 2d.In the mmprobed it consists of options like stuff parametric quantities there we must give the sample inside informations whether it as Fe or permalloy.When we click on portion geometry option at that place we can see portion tallness, portion thickness, portion widthness and cell size these should be changed harmonizing to user use. Then mmdisp will demo the loops that take topographic point for a sample. The mmdatatable will demo the values for the sample when loop is traveling on they are entire energy, demagnetisation energy, loops, Max angle, exchange energy, Anisotropy energy, Zeeman energy. Then mmgraph will demo the graph that can be opened harmonizing to user use. They can open two to three or many graphs can be opened harmonizing to user ‘s use.
2 ) Detailss of sample:
Samples utilizing here are iron and permalloy.The values are given below
Ms ( A/m )
A ( J/M )
Kl ( J/M ) 3
In this OOMMF the stuff parametric quantities must be taken either Permalloy or iron.For these elements the portion geometry will be changed. The portion tallness, portion breadth, thickness and cell size must be keep alteration until the concluding stable consequence is observed.
3 ) Consequences and treatments:
a ) For Permalloy
1. For the dimensions portion breadth ( m ) -40e-9, portion height – 40e-9, thickness-4e-9, cell size-2e-9
From the above figure we can reason that full part is in diagonal so that ‘s it is square in form. As it is square form the longest side will lies on the diagonal. As external field is non applied means the dipoles will be in longer axis. Then easy axis lies towards the plane.
The demagnetization energy from the graph will get down lessenings up to a point and after a certain point it starts saturating.Then exchange energy additions invariably and the anisotropy here is zero since all dipoles are revolving towards the same way merely so entire energy remains changeless. The exchange energy dominates here the demagnetization energy. The entire loops taken topographic point here is 4063.
2. for the dimensions partwidth-44e-9, portion height-40e-9, thickness-4e-9, cellsize-2e-9
For the above values the easy axis lies on plane due to the sample values. As the sample obtain here is rectangular the dipoles rotates towards the longer side of the rectangle. Then dipoles are non confronting diagonally as in instance of square. The dipole attempts to revolve to longer side of the rectangle from the diagonal. The anisotropy value is zero because the dipoles are revolving here towards the same way. The demagnetization energy reduces and so saturates after a certain point. Here the exchange energy dominates the demagnetization energy. We can besides reason that the entire energy here increases bit by bit. There is no Zeeman Effect issue because there is no external electric field is applied. Number of loops takes here is 6183.
3. for the dimensions partwidth-46e-9, portion height-40e-9, thickness-4e-9, cellsize-2e-9
The dipole here tries to revolve towards the longer side of the rectangular sample, which is the length of the sample. In the loop figure we can detect that dipoles are indicating towards longer axis but the borders of dipoles are deviating. This could be possible when the dipoles moves from North Pole to South Pole and besides it can be observed that dipoles are besides deviating at certain border of the rectangle. Zeeman Consequence does non be here because as there is no external electrical field is applied to it. The demagnetization energy in graph goes diminishing and after a certain point it starts saturates this implies after a certain point the Permalloy can non be demagnetized farther. The anisotropy energy remains zero. Then entire energy and exchange energy remains to be changeless. Then exchange energy dominates the demagnetization energy.
4. for the dimensions partwidth-56e-9, portion height-40e-9, thickness-4e-9, cellsize-2e-9
From the above figures it can be conclude that the easy axis lies on the plane. The dipoles are towards the longer axis that is length of the sample. The anisotropy energy is zero but shape anisotropy Acts of the Apostless on it because the sample depends on the form. The entire figure loops takes topographic point here is 5646.The entire energy here remains changeless and exchange energy additions bit by bit. The demagnetized field starts cut downing and after certain clip it starts saturates. The Zeeman Energy does non be here because as there is no external field is applied on it. The exchange energy dominates here the demagnetization energy. In this sample the anisotropy is zero because here uniaxial anisotropy is changeless.
5. for the dimensions partwidth-70e-9, portion height-40e-9, thickness-4e-9, cellsize-2e-9
Here besides the dipoles are traveling towards to the longer side that is the length of the sample. And the dipoles starts deviating to the border of the rectangle it could be possible because the dipoles move towards from North Pole to South Pole in a magnet. The easy axis here besides lied on the plane of sample. The Zeeman energy is zero because as there is no external field is applied to it. Then entire energy remains to be changeless and the demagnetization energy bit by bit reduces after a certain point and so it starts to saturate. Then exchange energy bit by bit increases and the anisotropy energy is zero. Then form anisotropy Acts of the Apostless on the sample and anisotropy is zero because uniaxial anisotropy is changeless. The figure of loops takes topographic point here is 3031.The Bloch walls plays an of import function in Permalloy than Neels walls.
6. for the dimensions partwidth-94e-9, portion height-40e-9, thickness-4e-9, cellsize-2e-9
Here in the above graphs we can reason that Zeeman energy is zero because there is no external field is applied to it. Then dipoles starts traveling towards to its axis which is gives the length of the sample. The Zeeman Energy does non be because as there is no external electrical field is non applied on it. Number of loops takes topographic point here is 2836.The anisotropy is zero but besides the form anisotropy starts moving on the sample. Neels walls play an of import function in Permalloy so Bloch walls. The demagnetization energy reduces bit by bit so it starts to be in impregnation and the exchange energy additions bit by bit. Then entire energy remains changeless. Then here exchange energy here dominates here the demagnetization energy.
B ) For Fe
1. for the dimensions partwidth-420e-9, portion height-420e-9, thickness-60e-9, cellsize-5e-9
From the above graphs we can see the formation of individual whirl. Then demagnetization energy dominates here the exchange energy. The exchange makes here the dipoles to aline homogenously but the demagnetization energy dominates here the exchange energy and forms the sphere wall. The anisotropy energy is non zero as in instance of permalloy.Here three-dimensional anisotropy Acts of the Apostless on it. Then net magnetization energy is zero here at the Centre of the sphere wall. Entire energy additions here bit by bit. Here besides Zeeman energy will non be because as there is no external field is applied to it. The entire loop takes topographic point here is 3736.
2. for the dimensions partwidth-480e-9, portion height-240e-9, thickness-60e-9, cellsize-5e-9
Here we can detect a formation of two sphere walls with two whirls this is due to formation of Bloch walls. Bloch walls are observed in this sample because to the thickness of the sample. If there is addition in thickness of sample there is a opportunity of formation of Neels walls instead than Bloch walls. The demagnetization energy dominates the exchange energy. Number of loops takes topographic point here is 2027.The Cubic anisotropy Acts of the Apostless on it. Zeeman Effect here is nothing because as there is no electrical field is applied to it.
3. for the dimensions partwidth-540e-9, portion height-240e-9, thickness-60e-9, cellsize-5e-9
We can see the different figure of vortex formation in the sphere construction. Demagnetisation energy here is minimal here every bit compared to the exchange energy. Since the length of sample additions this causes formation of two sphere walls. The net magnetization energy at the Centre of two sphere walls is zero. Cubic anisotropy Acts of the Apostless on it. Entire figure of loop issues here is 2568.And the Zeeman energy is zero and the entire energy additions bit by bit.
4. for the dimensions partwidth-660e-9, portion height-240e-9, thickness-60e-9, cellsize-5e-9
Here the demagnetization energy is really high so compared to the exchange energy. Since the exchange energy makes dipoles to be aligned homogenously and the demagnetization energy dominates the exchange energy and leads to organize sphere walls. Increase in the dimension of the sample tends to give us three closing domains whirls. In this construction we obtain high demagnetization energy. Entire energy additions bit by bit and the net magnetization formed at the Centre of sphere walls is zero. The figure of loops takes topographic point here is 6359.
5. for the dimensions partwidth-800e-9, portion height-240e-9, thickness-60e-9, cellsize-5e-9
From above figures we can reason that sample as high demagnetization energy as compared to the exchange energy. The Centre formed in this sample may be because of high exchange energy compared than to the demagnetization energy which aligns the dipoles in a homogeneous way. The net demagnetization energy formed at the 2nd sphere wall is zero. But possible the net magnetization at the Centre of first sphere wall may be a non-zero value. Cubic anisotropy Acts of the Apostless on it. Zeeman Energy here is nothing because as no electric field is applied to it.
6. for the dimensions partwidth-300e-9, portion height-240e-9, thickness-60e-9, cellsize-5e-9
The figure of loops takes topographic point here is 1741.A individual whirl formed and one sphere wall exist here. The dipoles makes to aline by exchange energy to be homogenously but here demagnetization energy dominates here exchange energy and leads to organize sphere walls.net magnetization at the Centre of sphere wall may be leads to nothing. As there if addition in thickness value takes topographic point so Bloch walls are formed.
4 ) Decision:
The above survey was made on the magnetic belongingss of Fe and Permalloy utilizing the OOMMF package. As Fe is a difficult magnetic stuff and Permalloy is a soft magnetic stuff, the net magnetization obtained for this samples are different. Here we had investigated on some many energies like Demagnetisation energy, Zeeman energy, and Anisotropy energy and about entire energy as the consequences displayed in the above. In the absence of any applied magnetic field the entire energy is sum of the all single energies. The Zeeman Effect is Zero because as there is no external field is applied. Here we have observed that as there is an addition in thickness of stuff it can take to from the Neels wall or Bloch wall. Hence Neels walls are found when we observe lower thickness and big wall is formed at higher thickness. The dimension of the sample plays an of import function for sphere wall formation in Fe and dipoles rotary motion in both the samples. This all where illustrated in the instance of Fe and Permalloy shown above.