Researchers at Hiroshima University, CNRS, and Université de Strasbourg synthesized crystals with magnetic properties that can change continuously and reversibly, a world first.
The study was highlighted as a cover article of the journal “Inorganic Chemistry,” a publication of the American Chemical Society in March 2016.
Recently, the scientific community has had immense interest in new types of magnets with the potential to create the next generation of energy efficient devices through innovations using materials science techniques.
Common magnets, like those holding reminders on home refrigerators or turning car motors, are made of metal and metal oxides. Newer magnets can be made with organic molecules and can have a range of magnetic behaviors because of variations in their molecular structure.
That range of behavior includes the strongly magnetic ferrimagnetic state and the very weakly magnetic spin glass state.
The different seasons in Hiroshima, Japan can affect the humidity inside office and research buildings throughout the year. Crystals prepared in different seasons showed different magnetic properties even though their crystal structures were almost identical.
“To find the source of the different magnetic states, we prepared the crystals under controlled conditions of temperature and humidity,” said Li Li, first author of the research paper and a Ph.D. student in the Department of Chemistry at Hiroshima University.
The crystals synthesized by the research team can exist in either the ferrimagnetic or spin glass state, depending on the conditions of how they are synthesized. This is the first material known to reversibly and continuously transition between magnetic states.
As the crystals absorb water from the air, they undergo subtle structural changes responsible for the continuous transformation between ferrimagnet and spin glass. By applying pressure, the effect can be reversed. This allows fine-tuning of the magnetic states, and explains why the humidity in the research lab can affect the crystals.
Using the research team’s synthesis methods, increasing the pressure on the crystal changes the spin glass state into the ferrimagnet state and drying the crystal changes ferrimagnet into spin glass. Pressure and humidity are like dimmer switches to slide the crystal back and forth between the two states.
Additionally, the crystal is chiral, meaning it can exist in either one orientation or its own mirror image. These mirror image versions of the molecule are not superimposable, like right and left human hands.
Both right-handed and left-handed versions of the crystals can transition between the ferrimagnet and spin glass states. However, there are valuable applications exclusive to chiral molecules due to their unique chemical and optical properties.
“Our laboratory primarily researches chiral magnets, but this is the first time we found one compound with multiple magnetic states,” said Katsuya Inoue, Ph.D., one of the researchers involved and the leader of Hiroshima University’s Center for Chiral Science.
Chiral magnets can be used in spintronics devices, which are the current state-of-the-art data storage technology that use less power, are faster, and can store more information than previous generations of computer hard drives.
“We imagine that a chiral material with two or more magnetic states will provide further technological advantages because of its handedness,” said Inoue.
“This is a brand new breed of molecular material and it requires finesse to synthesize. Our results might not lead directly to immediate practical applications, but advances made in the science of chiral magnets are generating properties not experienced before, opening a bright future of new innovations,” said Inoue.
Transporting power sources in the coldest places may be easier with a new re-chargeable, non-metallic battery from Japan. This “eco battery” could provide portable sources of power in environments like refrigerated factories or extreme winter environments.
Chemists from Hiroshima University developed a new synthesis method for organic radical batteries that are re-chargeable and continue to function at below-freezing temperatures. The specific model prototyped by the Hiroshima University team has greater voltage than previously reported styles from other research groups around the world. The method used to create this battery is an improvement on a report from the same Hiroshima University laboratory earlier in 2016.
Most electrical devices use a lithium-ion battery. Lithium-ion batteries are safer than standard lithium metal batteries, but both styles rely on metal, a finite resource that is in decreasing supply. The same problem of decreasing supply exists for copper and cobalt batteries, like the traditional AA batteries in TV remote controls.
Organic radical re-chargeable batteries have the potential to be cheaper, safer, and longer-lasting than current metal-based batteries, earning them the “eco battery” title. This style of battery can re-charge faster than meal-based batteries, the difference of one minute instead of one hour, because they carry energy chemically rather than physically.
Hiroshima University (広島大学 Hiroshima Daigaku?), in the Japanese cities of Higashihiroshima and Hiroshima, was established 1929 by the merger of a number of national educational institutions.
Under the National School Establishment Law, Hiroshima University was established on May 31, 1949. After World War II, the school system in Japan was entirely reformed and each of the institutions of higher education under the pre-war system was reorganized. As a general rule, one national university was established in each prefecture, and Hiroshima University became a national university under the new system by combining the pre-war higher educational institutions in Hiroshima Prefecture.
The new university combined eight component institutions: Hiroshima University of Literature and Science, Hiroshima School of Secondary Education, Hiroshima School of Education, Hiroshima Women’s School of Secondary Education, Hiroshima School of Education for Youth, Hiroshima Higher School, Hiroshima Higher Technical School, and Hiroshima Municipal Higher Technical School. In 1953, the Hiroshima Prefectural Medical College was added to the new Hiroshima University.
Some of these institutions were already notable. Above all, Hiroshima School of Secondary Education, founded in 1902, had a distinguished place as one of the nation’s two centers for training middle school teachers. The Hiroshima University of Literature and Science was founded in 1929 as one of the national universities and, with the Hiroshima School of Secondary Education which was formerly affiliated to it, were highly notable.
The present Hiroshima University, which was created from these two institutions as well as three other “old-system” training institutions for teachers, continues to hold an important position among the universities and colleges in Japan. Hiroshima Higher Technical School, which has many alumnae in the manufacturing industry, was founded in 1920 and was promoted to a Technical College (Senmon Gakko) in 1944. Hiroshima Higher School was founded in 1923 as one of the pre-war higher schools which prepared students for Imperial and other government-supported universities. Although these institutions suffered a great deal of damage due to the atomic bomb that was dropped on Hiroshima on August 6, 1945, they were reconstructed and combined to become the new Hiroshima University. Graduate schools were established in 1953. Hiroshima University relocated to Higashihiroshima from Hiroshima City between 1982 and 1995.
The Latest Updated Research News:
Hiroshima University research articles from Innovation Toronto
- Organic radical re-chargeable batteries for extreme winter environments at the moment – May 22, 2016
- New electronic stethoscope and computer program diagnose lung conditions – February 25, 2016
- Twisting magnets devices could have unprecedented data storage capacity – February 14, 2016
- Terahertz wireless technology could bring one hundred gigabits per second speeds out of a fiber – February 11, 2016
- New membrane may solve fresh water shortages – December 6, 2015
- Wearable equipment supports human motion where and when needed: Easier, Faster, Stronger, and More enjoyable – December 2, 2015
- SEnS soft exoskeleton enhances sensorimotor functions
- Sushi freezing techique could allow cryopreservation of internal organs
Hiroshima University, the National Institute of Information and Communications Technology, and Panasonic Corporation announced the development of a terahertz (THz) transmitter capable of signal transmission at a per-channel data rate of over ten gigabits per second over multiple channels at around 300 GHz. The aggregate multi-channel data rate exceeds one hundred gigabits per second. The transmitter was implemented as a silicon CMOS integrated circuit, which would have a great advantage for commercialization and consumer use.
This technology could open a new frontier in wireless communication with data rates ten times higher than current technology allows.
Details of the technology were presented at the “International Solid-State Circuit Conference (ISSCC) 2016,” held from January 31 to February 4 in San Francisco, California.
The THz band is a new and vast frequency resource not currently exploited for wireless communications. Its frequencies are even higher than those used by the millimeter-wave wireless local area network (from 57 GHz to 66 GHz), and the available bandwidths are much wider.
Since the speed of a wireless link is proportional to the bandwidth in use, THz is ideally suited to ultrahigh-speed communications.