(Ba,Sr)TiO3 tunable capacitors with RF commutation quality factors exceeding 6000

Meyers, Cedric J. G.; Freeze, Christopher R.; Stemmer, Susanne; York, R.A.

doi:10.1063/1.4961626

Cited by 37 publications

(29 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…From the 2θ XRD data for the (002) peak, the out-of-plane (OOP) lattice parameters of BST and LSMO layer are determined as 3.956A • and 3.843A • , respectively. These are very close to the bulk lattice parameters of BST (3.965A • ) [1][2][3][4][5][6][7] and LSMO (3.870A • ) 12,13 layers. The estimated strain for BST and LSMO layers along the c-direction is ∼0.2% and 0.7%, respectively, which is attributed to unrelaxed thermal and defect-induced strain, and some additional unrelaxed lattice mismatch strain for the BST (delete LSMO and insert BST) layer grown on the LSMO (delete BST and insert LSMO).…”

Section: Resultssupporting

confidence: 73%

“…The magnetic response is not saturated under a 300 Oe field, hence, it is expressed only in magnetic moment (emu), not in emu/cc. [1][2][3][4][5][6][7] The enhancements in H c and H EB at low temperature appears to be directly related to the ferroelectric nature of BST layer, and the resulting strain (∼0.4%) and/or charge redistributions that take place as the BST layer transformed from the cubic (paraelectric) to tetragonal (ferroelectric) phase at low temperature (200K). 18 This may also be consistent with the number of previous reports [19][20][21][22] on the formation of an antiferromagnetic region or layer due to strong pinned spins and magnetic depletion layer observed at various ferromagnetic and ferroelectric interfaces.…”

Section: Fig 2 Magnetic Moment Vs Temperature (M-t) Curves Of Lsmomentioning

confidence: 99%

“…For this study a concentration of Ba 0.4 Sr 0.6 TiO 3 (BST) is chosen, which is cubic and paraelectric at the (delete) ambient temperature, and then transforms to a ferroelectric tetragonal phase upon cooling through the Curie temperature (T C ) at 200K. 4 Previous workers [1][2][3][4][5][6][7] have deposited BST thin films on oxide substrates such as MgO, LaAlO 3 , SrTiO 3 , and Al 2 O 3 . However, high single crystal cost and small size are their (delete) major drawbacks of such substrates.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Exchange bias in Ba0.4Sr0.6TiO3/La0.7Sr0.3MnO3 heterostructures

2017

View full text Add to dashboard Cite

This work relates to the integration of the two-layer stack of the proposed multiferroic structure onto silicon substrates. Ba1-xSrxTiO3 is an excellent material for room-temperature voltage-tunable dielectric applications due to its high (ε=6000) dielectric constant. In this study we choose a composition of Ba0.4Sr0.6TiO3 (BST), which is cubic and paraelectric at 300K, and transforms to a ferroelectric tetragonal phase upon cooling through the Curie temperature (TC) at 200K. The main focus of the present work is to study what happens when BST is placed in contact with a room temperature ferromagnetic layer such as La0.7Sr0.3MnO3 (LSMO). In this study, the magnetic properties of a BST (200nm)/LSMO (63nm) heterostructure was compared to that of a single LSMO layer (63nm). Both films were deposited onto MgO/TiN buffered Si (100) using pulsed laser deposition (PLD) and a domain matching epitaxy (DME) paradigm. X-ray diffraction (XRD) measurements showed that these films were of single phase and epitaxial in nature, with an unrelaxed lattice strain of ∼0.2% that was predominately composed of thermal and defect-induced strain. The magnetic measurements showed that the Curie temperature (TC) of LSMO remained unchanged at 350K when the BST was in contact with the LSMO layer. Interestingly, at 4K both the coercive field (Hc) and the exchange bias (HEB) of the BST/LSMO heterostructure as compared to the lone LSMO film increased significantly from 400 to 800 Oe and from 155 to 305 Oe, respectively. These differences were found to disappear above 200 K, the ferroelectric TC of the BST over-layer. This strongly suggests that the observed changes in the magnetic behavior of the heterostructure was the result of stress and/or charge redistributions that resulted when the BST layer transformed from the cubic (paraelectric) to tetragonal (ferroelectric) phase at low temperature.

show abstract

Section: Resultssupporting

confidence: 73%

Section: Fig 2 Magnetic Moment Vs Temperature (M-t) Curves Of Lsmomentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Exchange bias in Ba0.4Sr0.6TiO3/La0.7Sr0.3MnO3 heterostructures

2017

View full text Add to dashboard Cite

show abstract

“…Usually CQF is used to calculate the figure of merit of devices [2,10], but not of a FE material (Fig. 7).…”

Section: Experiments and Discussionmentioning

confidence: 99%

“…Voltage-controlled passive (tunable filters, phase shifters, reconfigurable antenna arrays, etc.) and active (frequency multipliers and mixers) devices of MW microelectronics can be realized on the basis of FE films [1][2][3][4]. The devices based on FE films have high tuning speed, low power consumption, high power handling capability and low cost.…”

Section: Introductionmentioning

confidence: 99%

Separation of the Metallic and Dielectric Losses of Tunable Ferroelectric Capacitors Under Control Dc Voltage

Kotel'nikov¹,

Osadchy²,

Platonov³

et al. 2018

PIER Letters

View full text Add to dashboard Cite

Abstract-An approach to separate the metallic and dielectric losses in ferroelectric capacitors in all range of tuning under control dc voltages (U dc ) is considered. The procedure is based on measurements of the dc voltage dependencies of microwave losses (tan δ t (U dc )) and capacitance (C(U dc )) for a set of capacitors with similar layout but with different nominals. Linear extrapolation of tan δ t (C) dependencies at different control dc voltages to C = 0 allows to evaluate the dielectric losses tan δ d as a function of the control dc voltage. The procedure of separation was performed for a set of sandwich metal/(Ba 0.5 Sr 0.5 )TiO 3 /metal capacitors. Capacitors parameters were measured at a frequency of 2 GHz in a range of electric field strength in ferroelectric of E = (0 − 30) V/µm. The intrinsic commutation quality factor of BSTO film itself was estimated by the method proposed.

show abstract

Travelling waves in discrete electrical lattice with nonlinear symmetric capacitor

Motcheyo¹,

Fezeu

Siewe

et al. 2022

J Comput Electron

View full text Add to dashboard Cite

We study the propagation of voltage in a model of the conventional right-handed transmission line with a nonlinear symmetric capacitor. Applying the quasidiscrete approximation to the nonlinear voltage equation of the line, we derive a nonlinear Schrödinger equation and find the bright and dark solutions which are used as the initial condition for the integration of the nonlinear lattice model. The full integration of the lattice shows the propagation of the nonlinear voltage in the right-hand side and its robustness in the time. The density energy of the lattice at each time has a node around which bright voltage is localized while in the case of dark voltage, it has a node where it seems to drop to zero at the soliton centre.

show abstract

(Ba,Sr)TiO3 tunable capacitors with RF commutation quality factors exceeding 6000

Cited by 37 publications

References 16 publications

Exchange bias in Ba0.4Sr0.6TiO3/La0.7Sr0.3MnO3 heterostructures

Exchange bias in Ba0.4Sr0.6TiO3/La0.7Sr0.3MnO3 heterostructures

Separation of the Metallic and Dielectric Losses of Tunable Ferroelectric Capacitors Under Control Dc Voltage

Travelling waves in discrete electrical lattice with nonlinear symmetric capacitor

Contact Info

Product

Resources

About