Electric Field Control of Magnetic Properties in Multiferroic Heterostructures PDF Download

Author: Weigang Yang
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description

Author: Ming Liu
Publisher: John Wiley & Sons
ISBN: 3527803696
Category : Science
Languages : en
Pages : 305

View

Book Description
Written by well-known experts in the field, this first systematic overview of multiferroic heterostructures summarizes the latest developments, first presenting the fundamental mechanisms, including multiferroic materials synthesis, structures and mechanisms, before going on to look at device applications. The resulting text offers insight and understanding for scientists and students new to this area.

Author: Sen Zhang
Publisher: Springer Science & Business Media
ISBN: 3642548393
Category : Science
Languages : en
Pages : 143

View

Book Description
This book mainly focuses on the investigation of the electric-field control of magnetism and spin-dependent transportation based on a Co40Fe40B20(CoFeB)/Pb(Mg1/3Nb2/3)0.7Ti0.3O3(PMN-PT) multiferroic heterostructure. Methods of characterization and analysis of the multiferroic properties with in situ electric fields are induced to detect the direct magnetoelectric (ME) coupling. A switchable and non-volatile electric field control of magnetization in CoFeB/PMN-PT(001) structures is observed at room temperature, and the mechanism of direct coupling between the ferroelectric domain and ferromagnetic film due to the combined action of 109° ferroelastic domain switching in PMN-PT and the absence of magnetocrystalline anisotropy in CoFeB is demonstrated. Moreover, the electric-field control of giant magnetoresistance is achieved in a CoFeB-based spin valve deposited on top of (011) oriented PMN-PT, which offers an avenue for implementing electric-writing and magnetic-reading random access memory at room temperature. Readers will learn the basic properties of multiferroic materials, many useful techniques related to characterizing multiferroics and the interesting ME effect in CoFeB/PMN-PT structures, which is significant for applications.

Author: Stephen Mingda Wu
Publisher:
ISBN:
Category :
Languages : en
Pages : 180

View

Book Description
The electric field control of ferromagnetism has been a long sought after effect, due to the large number of potential applications in electronic/magnetic devices. Large currents (and hence large powers) are required to generate the large magnetic fields needed to control the magnetization of a ferromagnetic material in a thin film electronic device, which is incompatible with planar integrated circuit technology. Alternatively, creating large electric fields at these scales requires minimal current (and hence minimal power) and is already well established. By exploiting a magnetoelectric material, magnetization can be manipulated in a scalable planar low-power device through the application of electric field. Using this type of device architecture could lead to huge advances in magnetic memory and storage, as well as provide a crucial first step to creating low-power spintronic devices as a replacement for traditional electronics that are reaching the limit of scaling. One possible way to achieve the electric control of ferromagnetism is by controlling exchange bias, the shift of a magnetic hysteresis curve along the applied field axis due to interface interactions between coupled antiferromagnetic (AFM) and ferromagnetic (FM) materials. If it is possible to shift exchange bias through the coercive field of the FM, magnetization can be reversed. Reaching this goal requires a careful understanding of antiferromagnetism, ferromagnetism and the interactions between the two when coupled (exchange bias). The main focus of this thesis will be the design, fabrication, characterization, and understanding of an electric field effect device where we are able to reversibly modulate between two exchange bias states with opposite polarity in a thin film ferromagnet by coupling it to a multiferroic (ferroelectric/antiferromagnetic) material. The multiferroic material BiFeO3 (BFO), an AFM and ferroelectric (FE) with coupled AFM/FE order parameters, is a prime candidate material for affecting change in exchange bias systems. When coupled to a thin film ferromagnet such as the colossal magnetoresistive manganite La0.7Sr0.3MnO3 (LSMO), one can envision a system where FE order is switched in BFO, which induces a change in AFM order in BFO, which induces a change in exchange bias in LSMO. Here, an electric field effect device is created using BFO as the dielectric and LSMO as the conducting channel to realize just such a system. Heteroepitaxially deposited BFO (3 nm)/LSMO (200 nm) heterostructures are grown on SrTiO3 (100) substrates and subsequently patterned into field effect devices using a fabrication process involving photolithography and argon ion milling. These devices are then characterized through magnetotransport measurements to characterize the magnetic properties of the LSMO channel with respect to BFO FE polarization. Through these measurements this thesis shows, for the first time, exchange bias is directly controlled with electric field without temperature cycling or any electric or magnetic field cooling/biasing. This effect is reversible and comes concurrently with the modulation of channel resistance (sometimes over 300%), the modulation of magnetic coercivity, and magnetic Curie temperature. Based on these results and the current understanding of exchange bias we propose a model to understand the electric control of exchange bias. In this model the coupled antiferromagnetic/ferroelectric order in BFO along with the modulation of interfacial exchange interactions due to ionic displacement of Fe3+ in BFO relative to Mn3+/4+ in LSMO cause exchange bias modulation.

Author: Andres Cano
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110582139
Category : Science
Languages : en
Pages : 431

View

Book Description
Multiferroics, materials with a coexistence of magnetic and ferroelectric order, provide an efficient route for the control of magnetism by electric fields. The authors cover multiferroic thin-film heterostructures, device architectures and domain/interface effects. They critically discuss achievements as well as limitations and assess opportunities for future applications.

Author: Mirza I. Bichurin
Publisher: CRC Press
ISBN: 0429949618
Category : Science
Languages : en
Pages : 280

View

Book Description
This book is dedicated to modeling and application of magnetoelectric (ME) effects in layered and bulk composites based on magnetostrictive and piezoelectric materials. Currently, numerous theoretical and experimental studies on ME composites are available but few on the development and research of instruments based on them. So far, only investigation of ME magnetic field sensors has been cited in the existing literature. However, these studies have finally resulted in the creation of low-frequency ME magnetic field sensors with parameters substantially exceeding the characteristics of Hall sensors. The book presents the authors’ many years of experience gained in ME composites and through creation of device models based on their studies. It describes low-frequency ME devices, such as current and position sensors and energy harvesters, and microwave ME devices, such as antennas, attenuators, filters, gyrators, and phase shifters.

Author: Ming Liu
Publisher: John Wiley & Sons
ISBN: 3527803629
Category : Science
Languages : en
Pages : 264

View

Book Description
Written by well-known experts in the field, this first systematic overview of multiferroic heterostructures summarizes the latest developments, first presenting the fundamental mechanisms, including multiferroic materials synthesis, structures and mechanisms, before going on to look at device applications. The resulting text offers insight and understanding for scientists and students new to this area.

Author:
Publisher:
ISBN:
Category : Ferromagnetic materials
Languages : en
Pages : 0

View

Book Description
The shortcomings of contemporary complementary metal oxide semiconductor (CMOS) technologies include increased power consumption, scalability, volatility, and device variability. New materials and novel devices are being investigated in this regard. Spintronic devices, which are normally based on magnetic materials, store and process data based on the modes of electron spins, rather than the presence or absence of charges as in the CMOS, are one possible approach. Numerous potential advantages of spintronic devices include its quick operational speed, low power requirement, and non-volatility. Two ferromagnetic materials suitable for creating spintronic devices are investigated in this dissertation study. Material properties, techniques for regulating the magnetization of materials, with both magnetic and electrical fields, and the development of devices useful for use in frequency modulations are all respectively detailed. The first section of this dissertation studies the magnetically-induced transparence (MIT) effect in Y3Fe5O12 (YIG)/Permalloy (Py) coupled bilayers. The measurement is achieved via a heterodyne detection of the coupled magnetization dynamics using a single wavelength that probes the magneto-optical Kerr and Faraday effects of Py and YIG, respectively. Clear features of the MIT effect are evident from the deeply modulated ferromagnetic resonance of Py due to the perpendicular-standing-spin-wave of YIG. We develop a phenomenological model that nicely represents the experimental results including the induced amplitude and phase evolution caused by the magnon-magnon coupling. This work offers a new route towards studying phase-resolved spin dynamics and hybrid magnonic systems. The second part of this dissertation discusses the research on the hexaferrite material, Zn2Y, and the prospect of controlling its magnetic characteristics by applying a dc voltage, which is akin to a bias electric field. The detection and investigation of the magnetoelectric (ME) effect for in-plane currents orthogonal to the hexagonal axis in single crystal and thin films of Zn2Y grown via liquid phase epitaxy. By applying a dc voltage, tuning of ferromagnetic resonance (FMR) was achieved in the hexaferrites. In addition to the frequency shift caused by the electrical tuning, magnetic properties of the material as a function of the input tuning power was also studied.

Author: Carlos A. F. Vaz
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description

Author: Ziyao Zhou
Publisher:
ISBN:
Category : Electromagnetism
Languages : en
Pages : 129

View

Book Description
In past decades, attracted by the increasing demand of compact, fast, and low energy consumption RF/microwave devices, many researchers have devoted their efforts to realizing electric field control of magnetism, instead of magnetic field. For instance, within traditional RF/microwave devices, ferromagnetic resonance are controlled by bulky, noisy, slow and energy consumption electromagnets. This limits its application in many important, low mass and energy consuming requirement carriers, such as aircraft, satellites, radars and communication devices. As a result, novel functional material, which can be integrated into non-volatile, light, and energy-efficient electronic devices, need to be discovered. Multiferroics, a composite material combined with ferromagnetic material and ferroelectric material, is widely studied as a great candidate for E-field tunable RF/microwave applications like tunable resonators, phase shifters, tunable inductors and tunable filters. The coexistence of ferroelectricity and ferromagnetism in multiferroics introduces interaction between ferroelectric property and ferromagnetic properties, therefore, allowing electric field (E-field) control of ferromagnetism through varying mechanism. In our work, different mechanism-based magnetoelectric (ME) coupling in multiferroics heterostructure was investigated for the development of novel generation, voltage-controllable, high-speed, compact RF/microwave devices with greater energy efficiency. irstly, ME coupling was realized in different magnetic thin film/ferroelectric slab heterostructures. By decreasing the saturation magnetization of Cr doping Ni magnetic thin film, large ME coupling in NiCr/PbZr0.52Ti0.48O3 (PZT) and NiCr/PbZn1/3Nb2/3O2.4(PbTiO3)0.6 (PZNPT) was obtained. Furthermore, non-volatile voltage impulse tunability was discovered through electric field-induced phase transition in FeGaB/PZNPT multiferroics heterostructure. Giant ME coupling coefficient ~3000 Oe cm/kV was observed at PZNPT phase transition points. In FeGaB/Pb0.8Sn0.2Zr0.52Ti0.48O3 (PSZT) magnetic/antiferroelectric multiferroic heterostructure, antiferroelectric-ferroelectric phase transition in PSZT substrate gives us another opportunity to realize the voltage impulse tunable magnetic properties. The non-volatile tunability with large ME coupling effect offers a great opportunity of E-field control of magnetism in real RF/microwave applications. Secondly, traditional deposition methods like sputtering, Pulsed laser deposition (PLD), or Molecular beam epitaxy (MBE) require a high fabrication temperature (>600 oC), which limits their application in integrated circuits. We used low temperature(oC) spin spray method to deposit ZnO thin film with good electric, optical and piezoelectric performance. Fe3O4/ZnO bilayer heterostructure was also deposited by spin spray method. Significant ME coupling effective field of 14 Oe was observed by ferromagnetic resonance (FMR) measurements, paved a way to the application of multiferroics heterostructure in real industry. Finally, in real RF/microwave ME devices, magnetic thin film/ferroelectric slab heterostructure requires a higher voltage(~600 V) to tune the magnetic properties, therefore restraining their application. Nevertheless, strain/stress mediated ME coupling in thin films heterostructure is limited by sample clamping effect. Therefore other mechanisms-induced ME coupling were also studied in our experiment. Large interfacial charge mediated ME coupling effective field of 40 Oe was achieved in Co0.3Fe0.7/Ba0.6Sr0.4TiO3 multiferroic heterostructure. The charge effect amplitude dependence of magnetic film thickness was systematically investigated in NiFe/SrTiO3 multiferroic heterostructure. Lastly, the ME coupling in CoFe/BiFeO3 (BFO) heterostructure induced by interfacial exchange coupling between CoFe moment and canted moment in BFO was studied quantitively by FMR measurements.