The Development Of Memory And Storage Devices

microSD card

In the computing world, there is a lot of excitement over the technological advancements that that take place such as augmented reality, driverless cars, smart homes, artificial intelligence, voice control etc. But none of this would matter if there were no memory storage devices that could read and transfer data quickly and reliably. This is what drives everything else.

The search for reliable devices has always been a major concern for individuals and businesses for many years. Only a few pioneers have been able to contribute to the industry. One such individual worthy of this mention is Hardayal Singh Gill.

Hardayal Singh Gill is a distinguished engineer in the field of data storage and memory devices. A Ph.D. in Solid State Physics from the University of Minnesota. A former employee at Hewlett Packard Labs, IBM Corporation, Hitachi Global Storage Technologies and Western Digital Corporation. In his career, he has been credited with issuing more than 320 US Patents on “Memory and Recording Components.”


His insights and experience allowed him to gain a deeper understanding of the significance of memory and storage devices.

What makes him a key figure in the field of memory and storage devices? Hardayal Singh was elected an IEEE fellow in 1995 for his contributions to Magnetic Recording heads for Hard-Disk Drives.

As a visionary and innovator, Hardayal Singh’s accomplishments can be held on the pedestal with some of the early contributors in the field of storage devices. He pushed the boundaries of innovation and introduced ways on how magnetic thin films can be used to increase the reliability and performance of storage devices. Light and efficient storage devices have a myriad of applications in computers, smartphones, motion sensors, databases and smartcards.


This extensive range of application puts Hardayal Singh well in the context of being an expert. His reputation precedes him as he was the first one to apply Magnetoresistive (MR) heads to HDD while working at IBM Corporation.

A conventional MR sensor is commonly used in high capacity disk drives. These are prevailing sensors used because of their ability to read data from any disk surface. They can also read disks with linear densities and greater track than a thin film inductive head.

Why are Storage Devices important?

Computer devices used to fill up entire rooms. These devices were not portable at all. The amount of data carried by these storage and memory devices was exponentially low and yet carried an exuberant amount of physical space.


Whether it’s a photo album, personal music collection, or an organization running a critical business system, data storage has always been a necessity for everyone today. The technology has undergone a major evolution since it was first introduced.

Computers are now smaller, portable while becoming increasingly capacious and efficient in storing data. Storage capacity in a computing device is a key factor that determines its value for money.

Given all these applications, there are extensive uses of storage and memory devices in the business world. All businesses have unique storage demands, where the data is accessed frequently. Efficient readability allows the data to be altered and accessed with ease.


None of those mentioned above technologies have been made possible without a century of steady engineering and scientific minds working behind it. From the invention of magnetic tape that took place in 1928, all the way to cloud technologies, storage devices have undoubtedly come a long way.

In 1980, Hardayal Singh designed and developed bubble memory chips of the highest capacity (4M bit) in collaboration with the National Semi-Conductor design group.

Bubble memory chips are non-volatile memory that makes extensive use of thin magnetic material. It was slated to be the future of memory storage devices with the potential to play both primary and secondary roles. The technology was then made obsolete being replaced by DRAM and HDD.


The size of storage devices that exist today is important in terms of their use for multiple reasons. These devices are portable and much secure than ever. For instance, flash drives, USB devices, External Hard Drives etc. are all used for personal and professional purposes all over the world.

Challenges of Storage and Memory Devices

Storage and management large amounts of data over time. We are living in the information age. The rate at which data is growing the capacity, cost, performance and stability are seen as ideal factors for all storage solutions.

Despite all the challenges mentioned above, reliability has always been a major concern. The reliability of any memory device is measured on its ability to retrieve data without causing any loss in data. The primary purpose behind the research of Hardayal Singh was to ensure that a thin magnetic strip being used in the storage device. When the device components are smaller, the device itself becomes portable enough.


Hardayal Singh has carried out several pieces of research to address the majority of these challenges. Some of the most notable ones are based on magnetic tunnel junctions and how they can be improved using an insulated antiferromagnetic layer. Another research that has been among the most cited ones is on how to design tunnel junction head structure with causing any current shunting.

Magnetic Films in Storage Devices

Hardayal Singh designed the first giant magnetoresistance heads at IBM that was launched in the year 1997 and was honored for this contribution. His idea for using very thin anti-ferromagnetic material, negative delta M applied to Magnetic Tunnel Junction (MTJ) and giant magnetoresistance (GMR) heads for achieving self-pinned designs.

Magnetic films are an essential part of any electronic device. Therefore, it is important to understand the value of the shape, size, and thickness of the film used. Magnetic films are used for transferring data easily.


Magnetic films are used extensively because they make storing and transferring data easier. According to a study, it was shown that magnetic films reduce the energy required for data retrieval and storage by a factor of 10,000.

His ideas for using MJTs with perpendicular magnetic anisotropy are still widely used in the random-access memory (RAM) manufacturing.

Using thin ferromagnetic materials in data storage devices such as hard-disk can increase the flow of electrons in the device resulting in faster transfer of data. An MIT research showed that the use of thin ferromagnetic films could increase the performance of the device by a significant margin. Not only that, but it will also make the device far more reliable. Thin magnetic films are shockproof i.e. can handle falls better due to their flexible nature.

Using ferromagnetic material in these present inventions is directed to storage devices that can be implemented as heads for multiple disk drives. An MTJ has at least a couple of two separate layers of metallic antiferromagnetic layers and a very thin insulating tunnel barrier.

Hardayal Singh’s approach allowed its implementation in the magnetic sensor designs such as MRAM, recording disk drive, and non-violative memory cells. An MJT device can be used as a sensor for the magnetic field in magnetic HDD or MRAM array.

His invention allowed space for additional critical level observations. One of the major issues that he addressed in his work was the stabilization of the MJT device structure. He found a way to counter it through surrounding the free stack with hard bias material. His work recognizes the optimum stabilization while doing the hard-bias layer centered around the free stack.

The invention related to the magnetic tunnel junction Magnetoresistive sensors. It is used for reading information signals coming through a magnetic medium.

He also has been credited with constructing methods of innovator magnetic reset for self-penned designs. These designs were used for resetting the magnetic states of the free and reference layer for the entire wafer and row carriers.

Use of Antiferromagnetic Materials

One of the contributions of Hardayal Singh was the use of antiferromagnetic material in MTJ sensors. Antiferromagnetic materials improve the way information is written and read electrically in devices. They are microscopic magnets with opposite orientations. Computers nowadays use Silicon components, but they fail to be as efficient as antiferromagnetic materials.

Researchers and scientists for decades have identified anti-ferromagnetic materials. However, it is only recently that it got the attention it deserves. Nobel laureate Louis Néel concluded in his research the prospects of antiferromagnetic materials. The reason why antiferromagnetic materials are considered better than silicon components because they are immune to external magnetic fields.

Research shows that antiferromagnetic material has greater electrical conductivity. However, there was still one underlying issue; antiferromagnets have poor corrosion resistance. Its use was limited after this problem seemed to exist without a solution.

In 2001, his research showed that electrically insulating the antiferromagnetic material seemed to resolve the issue in storage devices. It was a major breakthrough that led to the development of many other future devices.

Also, naturally occurring magnets have different types of magnetism potential. Their magnetism is based on two main factors. First, the magnitude of the magnetic material moment and second is the direction that determines the torque experienced by the magnet from the external magnetic field. Based on this characterization, magnets are differentiated from each other.

The research further added that Anti-ferromagnetic materials are like ferromagnets, but their magnetic moments are anti-parallel to the neighboring moments. This alignment takes place spontaneously below the critical temperature, which is also known as Neel Temperature.

This material can correlate the change in the magnetic structure and can herald ultra-fast computer logic systems. There are several other possibilities as well, such as credit cards that cannot be erased using external magnetic fields.

The magnetism of an anti-ferromagnetic material gets aligned spontaneously when a magnetic field is applied and that too, at a temperature below the critical level. When the external field is removed, the material eventually retains its anti-parallel alignment.

This material is one of the most interesting elements to be found in nature. Growing researches have shown that anti-ferromagnetic material is known for having superconductivity. This material can behave like both ferromagnets and anti-ferromagnets. The corresponding magnetic and structural properties resemble the metal-insulator. As a consequence, there is a major change in the conductivity level when the field is applied.

Bottom Line

In this information age, memory and storage devices have immense significance. However, storage devices nowadays are not only smart and portable but multifunctional and secure as well. The devices that we see today are more of a derived version of how they look a couple of decades back.

Hardayal Singh Gill has been one of the earliest contributors in the field of memory and storage devices, and his work has led to many technological outbreaks. His academic and professional experience make him a visionary in the field with an adept appreciation for technology and how he can contribute more. As one of the most prominent and powerful voices in the tech industry, he uses his unparalleled skills in enlightening others with knowledge.