Newly Discovered Properties of Ferroelectric Crystal Shed Light on Emerging Branch of Materials
July 12, 2018 | AIP.orgEstimated reading time: 2 minutes
In ferroelectric materials the crystal structure distorts, giving rise to a spontaneously formed polarization and electric field. Because of this unique property, ferroelectrics can be found in anything from ultrasound machines and diesel fuel injectors to computer memory. Ferroelectric materials are behind some of the most advanced technology available today. Findings that ferroelectricity can be observed in materials that exhibit other spontaneous transitions, like ferromagnetism, have given rise to a new class of these materials, known as hybrid improper ferroelectrics. The properties of this type of material, however, are still far from being fully understood. New findings published in Applied Physics Letters, from AIP Publishing, help to shine light on these materials and indicate potential for new optoelectronic and storage applications.
A team of researchers from China has characterized one type of hybrid improper ferroelectric, Ca3Mn2O7. The group investigated the material’s ferroelectric, magnetoelectric and optical properties. They were able to demonstrate ferroelectricity in Ca3Mn2O7 as well as coupling between its magnetism and ferroelectricity, a key property that has potential to allow for faster and more efficient bit operations in computers.
“Our work solves a long-term puzzle in this field, which could push forward the frontiers and enhance the confidence to continue the research in this field,” said Shuai Dong, an author on the paper.
Like batteries, for instance, ferroelectrics have positively and negatively charged poles. A major distinguishing feature of these materials, however, is that this polarization can be reversed by using an external electric field.
“This can be useful because it can be used in devices to store information as ones and zeros,” Dong said. “Also, the switching of polarization can generate current, which can be used in sensors.”
Unlike traditional ferroelectrics, which directly derive their properties from polar distortions in the lattice of the material’s crystal, hybrid improper ferroelectrics generate polarization from a combination of nonpolar distortions.
When hybrid improper ferroelectrics were first theorized in 2011, two materials were proposed. In the years since, nonmagnetic Ca3Ti2O7 crystals were demonstrated experimentally, but a full characterization of its magnetic counterpart, Ca3Mn2O7, remained elusive.
“Multiple transitions as well as phase separations were evidenced in Ca3Mn2O7, making it more complex than the early theoretical expectations,” Dong said. “This material is complex, and the leakage is serious, which prevents the direct measurement of its ferroelectricity in high temperature.”
To further understand Ca3Mn2O7, Dong and his collaborators confirmed the material’s ferroelectricity using pyroelectric measurements that examine its electric properties across a range of temperatures as well as measured Ca3Mn2O7’s ferroelectric hysteresis loops, a method that mitigates some extrinsic leakage. Further investigation showed that Ca3Mn2O7 exhibits a weak ferromagnetism that can be modulated by an electric field.
It was found that Ca3Mn2O7, a material long-rumored to have ferroelectric and magnetoelectric properties, also exhibited strong visible light absorption in a band gap well suited for photoelectric devices. This feature of Ca3Mn2O7 might pave the way for the material to be used in anything from photovoltaic cells to light sensors with the built-in electric field leading to larger photogenerated voltage than today’s devices.
“The most surprising thing for us was that no one noticed its prominent light absorption before,” Dong said.
In the future, Dong said he hopes to explore Ca3Mn2O7’s photoelectric properties as well as investigate whether introducing iron to the crystal would enhance its magnetism.
Suggested Items
Groundbreaking Ceremony Marks the Beginning of a New Era for Newccess Industrial; The Construction of the MINGXIN Building
04/12/2024 | Newccess IndustrialOn a clear and sunny day in March, the groundbreaking ceremony for the MINGXIN Building took place in Shenzhen, China. This moment marked the official commencement of construction for a project that will reshape the semiconductor materials industry.
The Need for a Holistic Global Sustainability Standard
04/10/2024 | Michael Ford, Aegis SoftwareNo one can deny that the resources of our fragile planet are finite. The environment seems like a third party, subject to constant degradation. We’re acutely aware of the effects of pollution on our climate, and despite our “throw-away” culture, recycling and recovery of materials has remained relatively expensive, even as we use more energy just to survive.
iNEMI Publishes Four Roadmap Topics
04/04/2024 | iNEMIThe International Electronics Manufacturing Initiative (iNEMI) announces the availability of the first roadmap topics in the new iNEMI Roadmap format. Printed circuit boards, sustainable electronics, smart manufacturing, and mmWave materials and test are now available online.
Insulectro’s 'Storekeepers' Extend Their Welcome to Technology Village at IPC APEX EXPO
04/03/2024 | InsulectroInsulectro, the largest distributor of materials for use in the manufacture of PCBs and printed electronics, welcomes attendees to its TECHNOLOGY VILLAGE during this year’s IPC APEX EXPO at the Anaheim Convention Center, April 9-11, 2024.
Checking In With ICAPE Group
04/03/2024 | Nolan Johnson, I-Connect007ICAPE Group’s field application engineer Erik Pederson drills down on sustainability, supply chain resiliency, and what value engineering really looks like in this exclusive interview. Founded in 1999, European-based ICAPE Group provides 21 million printed circuit boards and over six million technical parts to manufacturers every month. With 30 PCB manufacturing partners globally and 50 partners providing a wide array of technical parts, ICAPE Group has operations in China, Taiwan, Thailand, South Korea, Vietnam, South Africa, Europe, Mexico, and the United States. The company also focuses on the value proposition for its customers.