Overview of Magnetic Bubble Memory Technology

Hi students, in the continuation of magnetic materials, So, now we are going to discuss the magnetic bubble memory. So, magnetic bubbles are soft magnetic materials. The magnetic domains with a few micrometers in diameter are embedded in a matrix with different orientations. The magnetic bubbles are similar to the magnetic disk memories. So, which are widely used in the computers. In magnetic bubble memories, the bubbles are moved electrically at high speed. In the bubble memories by using these magnetic disk memories or bubble memories to read out and storage of the information is reduces. So, coming to the examples of the main. Magnetic bubble memories, rare earth ortho ferrites, hexagonal ferrites, rare earth ferromagnetic garnets, amorphous bubble materials. These are the few examples of the magnetic bubble memories. So, in the magnetic film. Are these magnetic films which is made of ferrites or garnets. The magnetic domains look like a wavy strips. Wavy strips means the magnetic materials are arranged like this which are shown in figure. So these are the wavy strips. Wavy strips means they are displaced or they are movable. Already I told that. The magnetic bubbles are moved electrically at high speed. So the magnetic domains look like a wave strips. The magnetic strips are arranged in two ways. They are pointing up and pointing down. That means the magnetic strips are arranged from the top to bottom that is pointing down and they are also arranged from the bottom to top they are called as pointing up. When a polarizer light is applied on these materials. One set of strips appears as bright, another one appears as a dark. We know that any light is incident or falls on the obstacle, a part is in bright region. It's behind part is in dark. Similarly, here also same we can observe. So, when a polarizer light is subjected on the magnetic materials, so the front portion of these materials appears as bright. Their back portion or another strips appears as dark. So, the behavior of the strips. entirely different when varying magnetic field is applied in a direction perpendicular to the film or strips. So, when the magnetic field is gradually increases on the strips or domains. So, they opposes the applied magnetic field as a result they can begin to shrink. Sometimes saying here may So, when a when the when the magnetic field is subjected on the on the strips. So, thus at a particular magnetic field the magnetic strips opposes the external magnetic field as a result. So, they become shrink shrink shrink that means they will try to reduce their size. So, it is clearly observed in the diagram. In first portion the area of the strips is more in sec coming to the second diagram. So that area gradually decreases in third diagram after shrink so they become a bubble so that is the meaning. When I applied external magnetic field across a particular value, all the magnetic domains are suddenly concentrated in a small circular area of diameter in order to few micrometers. So, the external magnetic field is across at a particular value all the domains suddenly concentrated in a circular shape. shape and their diameter is in the order of a few micrometers. These small circular areas are known as magnetic bubbles or bubbles. So, the generated magnetic bubbles are stable in a particular applied region. So, the dependence of magnetic bubbles on the applied fields as shown in the figure. So, when the field across is the particular value or saturation value, the magnetic domain changes into the magnetic strips and hence decreases in a Bubble radius width takes place, bubble radius takes place. So, this is the magnetic bubble memory. I can explain in this slide. Magnetic bubbles memory is a type of computer memory, already I told that. It uses an epitaxially grown thin film of a materials such as ortho ferrites. and garnets coated on the substance. Garnet has a wavy domain structure. Wavy means vary or changes. So, the applied magnet, this is the actually for example, in this steps, in this graph, we are going to explain the applied magnetic field and the shape of the bubble or shape of the magnetic strips. So, the shape of the magnetic strips are shape means the shape of the magnetic strips gradually decreases. The shape takes along the x axis and applied magnetic field takes along the y axis. So, with increasing field, so the shape is maximum. So, the applied magnetic field reaches a particular value, the shape gradually decreases and it forms a bubble. So, all of you observed here, the strip domain actually this is shape of the strip. So, the applied magnetic field gradually increases, it reaches a particular value. The shape of the strips gradually decreases and it becomes a bubble or it forms a bubble. So, fully magnetized that is maximum bubble collapsing takes place. So, this graph explains the conversion of the strips that is magnetic strips into the bubbles. These bubbles having a less diameter with a few micrometers. For that let us take a permanent magnet. So, the schematic representation of the structure of the magnetic bubble is shown in figure. A a thin layer of magnetic garnet is grown epitaxially on the substance which is made by the non magnetic material. So, actually this is the non-magnetic frame. On this frame, the magnetic strips are arranged. So, on this magnetic strips, the magnetic field is subjected. up to a maximum value perpendicular to the strips, one set of strips appears as bright, remaining set appears as a dark. So, if the applied magnetic field reaches a particular value, so all the magnetic strips can be shrink and they becomes a bubble. Already I told that here already I am going to explain that. Such a gadolinium or gallium garnet of a diameter ranging of 20 to 40 nanometers. A permanent magnet is used to produce the required magnetic field. The conductor which is placed on the top of the surface of the device is used to produce the magnetic bubbles. So, the magnetic bubbles are rotated by employing the magnetic field produces by the set of three coils as shown in this figure. Actually it is non conducting or non magnetic material. So, on the non magnetic material the magnetic strips. or mountain elliptic epitaxially. So, by using a garnet or gadolinium, we are going to reduce the magnetic field on the magnetic strips perpendicularly. So, all the magnetic strips can be converted into the small bubbles. This is the structure of the magnetic bubble memory. So, the advantages of the magnetic bubbles, the magnetic bubble memory is non-volatile because of their small size, the density of the bubble is very high. If one bit of information is stored one bubble, one can store 10 million bit per centimeter square. Already I told that by using this magnetic bubbles we are gently reduces the readout and the storage of the information. So, some of the tab x are observed in this magnetic bubbles, there the magnetic bubbles memory is not a random axis therefore, the information must be read serially. So, the achievable speed may be few hundred kilobytes per second. That means main drawback of this means, so the information, the stored information can be read. serially that means, so at one time we can read some of the part after time after some time remaining data is not possible to read out that is the disadvantage. So, the magnetic bubbles are used in the this is the bubble model. So, this is a actually micro pusher chip and this is the another chip. In this type of chips we are going to use the magnetic bubbles and SD cards and FRAI. So, already it is a like a SIM card or memory card and this is the another type of the chips. So, in these chips we are going to use the magnetic bubble memories. So, this is the magnetic bubble memory and its applications.

The magnetic bubbles are similar to the magnetic disk memories. So, which are widely used in the computers. In magnetic bubble memories, the bubbles are moved electrically at high speed. In the bubble memories by using these magnetic disk memories or bubble memories to read out and storage of the information is reduces. So, coming to the examples of the main.

Magnetic bubble memories, rare earth ortho ferrites, hexagonal ferrites, rare earth ferromagnetic garnets, amorphous bubble materials. These are the few examples of the magnetic bubble memories. So, in the magnetic film. Are these magnetic films which is made of ferrites or garnets.

The magnetic domains look like a wavy strips. Wavy strips means the magnetic materials are arranged like this which are shown in figure. So these are the wavy strips. Wavy strips means they are displaced or they are movable.

Already I told that. The magnetic bubbles are moved electrically at high speed. So the magnetic domains look like a wave strips. The magnetic strips are arranged in two ways.

They are pointing up and pointing down. That means the magnetic strips are arranged from the top to bottom that is pointing down and they are also arranged from the bottom to top they are called as pointing up. When a polarizer light is applied on these materials. One set of strips appears as bright, another one appears as a dark.

We know that any light is incident or falls on the obstacle, a part is in bright region. It's behind part is in dark. Similarly, here also same we can observe. So, when a polarizer light is subjected on the magnetic materials, so the front portion of these materials appears as bright.

Their back portion or another strips appears as dark. So, the behavior of the strips. entirely different when varying magnetic field is applied in a direction perpendicular to the film or strips. So, when the magnetic field is gradually increases on the strips or domains. So, they opposes the applied magnetic field as a result they can begin to shrink.

Sometimes saying here may So, when a when the when the magnetic field is subjected on the on the strips. So, thus at a particular magnetic field the magnetic strips opposes the external magnetic field as a result. So, they become shrink shrink shrink that means they will try to reduce their size. So, it is clearly observed in the diagram.

In first portion the area of the strips is more in sec coming to the second diagram. So that area gradually decreases in third diagram after shrink so they become a bubble so that is the meaning. When I applied external magnetic field across a particular value, all the magnetic domains are suddenly concentrated in a small circular area of diameter in order to few micrometers.

So, the external magnetic field is across at a particular value all the domains suddenly concentrated in a circular shape. shape and their diameter is in the order of a few micrometers. These small circular areas are known as magnetic bubbles or bubbles. So, the generated magnetic bubbles are stable in a particular applied region. So, the dependence of magnetic bubbles on the applied fields as shown in the figure.

So, when the field across is the particular value or saturation value, the magnetic domain changes into the magnetic strips and hence decreases in a Bubble radius width takes place, bubble radius takes place. So, this is the magnetic bubble memory. I can explain in this slide. Magnetic bubbles memory is a type of computer memory, already I told that. It uses an epitaxially grown thin film of a materials such as ortho ferrites.

and garnets coated on the substance. Garnet has a wavy domain structure. Wavy means vary or changes.

So, the applied magnet, this is the actually for example, in this steps, in this graph, we are going to explain the applied magnetic field and the shape of the bubble or shape of the magnetic strips. So, the shape of the magnetic strips are shape means the shape of the magnetic strips gradually decreases. The shape takes along the x axis and applied magnetic field takes along the y axis. So, with increasing field, so the shape is maximum. So, the applied magnetic field reaches a particular value, the shape gradually decreases and it forms a bubble.

So, all of you observed here, the strip domain actually this is shape of the strip. So, the applied magnetic field gradually increases, it reaches a particular value. The shape of the strips gradually decreases and it becomes a bubble or it forms a bubble.

So, fully magnetized that is maximum bubble collapsing takes place. So, this graph explains the conversion of the strips that is magnetic strips into the bubbles. These bubbles having a less diameter with a few micrometers. For that let us take a permanent magnet. So, the schematic representation of the structure of the magnetic bubble is shown in figure.

A a thin layer of magnetic garnet is grown epitaxially on the substance which is made by the non magnetic material. So, actually this is the non-magnetic frame. On this frame, the magnetic strips are arranged. So, on this magnetic strips, the magnetic field is subjected. up to a maximum value perpendicular to the strips, one set of strips appears as bright, remaining set appears as a dark.

So, if the applied magnetic field reaches a particular value, so all the magnetic strips can be shrink and they becomes a bubble. Already I told that here already I am going to explain that. Such a gadolinium or gallium garnet of a diameter ranging of 20 to 40 nanometers. A permanent magnet is used to produce the required magnetic field. The conductor which is placed on the top of the surface of the device is used to produce the magnetic bubbles.

So, the magnetic bubbles are rotated by employing the magnetic field produces by the set of three coils as shown in this figure. Actually it is non conducting or non magnetic material. So, on the non magnetic material the magnetic strips.

or mountain elliptic epitaxially. So, by using a garnet or gadolinium, we are going to reduce the magnetic field on the magnetic strips perpendicularly. So, all the magnetic strips can be converted into the small bubbles.

This is the structure of the magnetic bubble memory. So, the advantages of the magnetic bubbles, the magnetic bubble memory is non-volatile because of their small size, the density of the bubble is very high. If one bit of information is stored one bubble, one can store 10 million bit per centimeter square.

Already I told that by using this magnetic bubbles we are gently reduces the readout and the storage of the information. So, some of the tab x are observed in this magnetic bubbles, there the magnetic bubbles memory is not a random axis therefore, the information must be read serially. So, the achievable speed may be few hundred kilobytes per second.

That means main drawback of this means, so the information, the stored information can be read. serially that means, so at one time we can read some of the part after time after some time remaining data is not possible to read out that is the disadvantage. So, the magnetic bubbles are used in the this is the bubble model. So, this is a actually micro pusher chip and this is the another chip.

In this type of chips we are going to use the magnetic bubbles and SD cards and FRAI. So, already it is a like a SIM card or memory card and this is the another type of the chips. So, in these chips we are going to use the magnetic bubble memories.

So, this is the magnetic bubble memory and its applications.

Transcript for:Overview of Magnetic Bubble Memory Technology

Transcript for:
Overview of Magnetic Bubble Memory Technology