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10 Spintronics Applications
the junction electrodes, all improvements made on spin valve sensor technology are
in general applicable here.
10.4.2 Background
The motivation behind the invention of spin valves and MTJs is the hard disk drive
applications. However, later they have been proved to be effective and beneficial
in the applications of memory devices too. Computer memories endowed with the
following attributes are having high demand. The attributes are as follows: (1) nonvolatility, (2) high density, (3) short cycle time, (4) low power consumption, (5)
low cost, (6) high reliability and (7) infinite lifetime. Precisely speaking, in case of
hard disk drive applications, the spin valves and MTJs are utilized as magnetic field
sensors. Such sensors sense the magnetic fields from the information bits, which
are nothing but nanosized magnet, recorded on the hard disks. In case of memory
applications, when those spin valves and MTJs are employed as cell elements, the
sensors themselves act to store the information. The basic structure of the memory
cell is still the same as that of the sensor. Noteworthy, in case of memory cell, the
saturation region of magnetization of spin valves and MTJs are utilized, whereas in
case of read head sensors, the linear region of magnetization is used.
10.4.3 Why MRAM Should Be Used?
DRAM has the advantage of being cheap but is comparatively slow and data are
lost when power is off. SRAM, on the other hand is faster than DRAM. But it can
cost up to four times as much as DRAM and data are lost when power is turned
off. FLASH memory saves data when the power is off, but the process is too slow
and consumes a lot of power. MRAM potentially combines the density of DRAM
and the high speed of SRAM and the non-volatility of FLASH memory or hard
disk, and all this is done using very less power. MRAM can resist high ionizing
radiation, can operate in extreme temperature conditions and thus is very suitable
for aerospace applications when combined with suitable CMOS technology. The
most prominent and vital characteristics of MTJs are their large magnetoresistance
values, high resistance and low operating voltage. Owing to these attributes, MRAM
devices are quite prospective for implementation in laptop computers so that it does
not need to boot up and in cell phones promising improved battery time and enhanced
capabilities.
10 Spintronics Applications
the junction electrodes, all improvements made on spin valve sensor technology are
in general applicable here.
10.4.2 Background
The motivation behind the invention of spin valves and MTJs is the hard disk drive
applications. However, later they have been proved to be effective and beneficial
in the applications of memory devices too. Computer memories endowed with the
following attributes are having high demand. The attributes are as follows: (1) nonvolatility, (2) high density, (3) short cycle time, (4) low power consumption, (5)
low cost, (6) high reliability and (7) infinite lifetime. Precisely speaking, in case of
hard disk drive applications, the spin valves and MTJs are utilized as magnetic field
sensors. Such sensors sense the magnetic fields from the information bits, which
are nothing but nanosized magnet, recorded on the hard disks. In case of memory
applications, when those spin valves and MTJs are employed as cell elements, the
sensors themselves act to store the information. The basic structure of the memory
cell is still the same as that of the sensor. Noteworthy, in case of memory cell, the
saturation region of magnetization of spin valves and MTJs are utilized, whereas in
case of read head sensors, the linear region of magnetization is used.
10.4.3 Why MRAM Should Be Used?
DRAM has the advantage of being cheap but is comparatively slow and data are
lost when power is off. SRAM, on the other hand is faster than DRAM. But it can
cost up to four times as much as DRAM and data are lost when power is turned
off. FLASH memory saves data when the power is off, but the process is too slow
and consumes a lot of power. MRAM potentially combines the density of DRAM
and the high speed of SRAM and the non-volatility of FLASH memory or hard
disk, and all this is done using very less power. MRAM can resist high ionizing
radiation, can operate in extreme temperature conditions and thus is very suitable
for aerospace applications when combined with suitable CMOS technology. The
most prominent and vital characteristics of MTJs are their large magnetoresistance
values, high resistance and low operating voltage. Owing to these attributes, MRAM
devices are quite prospective for implementation in laptop computers so that it does
not need to boot up and in cell phones promising improved battery time and enhanced
capabilities.