| 1. |
- Fors, Rickard, et al.
(författare)
-
Sol-gel derived versus pulsed laser deposited epitaxial La0.67Ca0.33MnO3 films : structure, transport and effects of post-annealing
- 2004
-
Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 467:02-jan, s. 112-116:467, s. 112-116
-
Tidskriftsartikel (refereegranskat)abstract
- Epitaxial La0.67Ca0.33MnO3 films have been prepared on LaAlO3 crystals by pulsed laser deposition (PLD) and by a novel all-alkoxide sol-gel technique. Different out-of-plane lattice parameters are found for the as-prepared films, and scanning electron microscopy shows a more porous structure for sol-gel films as compared to PLD films. These differences are largely removed by post annealing at 1000 degreesC. Transport measurements show maximum temperature coefficient of resistivity of 8.2% K-1 at 258 K (PLD) and 6.1% K-1 at 241 K (sol-gel) and colossal magnetoresistance at 560 kA/m of 35% at 263 K (PLD) and 32% at 246 K (sol-gel).
|
|
| 2. |
- Grishin, Alexander M., et al.
(författare)
-
Green and blue magneto-optical photonic crystals
- 2012
-
Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 520:9, s. 3647-3650
-
Tidskriftsartikel (refereegranskat)abstract
- A series of one-dimensional heteroepitaxial all-garnet magneto-optical photonic crystals (MOPCs) were pulsed laser deposited to operate at 550 and 470 nm wavelength. We explored the concept of blue shift of the optical absorption edge of ferric ions by substituting Fe with Ga on the tetrahedral sites as well as Bi and Y, respectively, with Ca and Ce at the dodecahedral coordinated positions. 17-layered [Y2Ce1Fe5O12/Gd3Ga5O12] MOPC with a total thickness of 968 nm demonstrates superior magneto-optical performance: Faraday rotation theta(Fmax) = + 2.0 degrees and transmittance as high as 0.35 at the resonance wavelength of 470 nm.
|
|
| 3. |
- Grishin, Alexander M., et al.
(författare)
-
Optical dispersion and temperature dependent latching-type magneto-optical properties of magnetron sputtered Bi3Fe3.34Ga1.66O12 (001) and (111) films
- 2020
-
Ingår i: Thin Solid Films. - : ELSEVIER SCIENCE SA. - 0040-6090 .- 1879-2731. ; 699
-
Tidskriftsartikel (refereegranskat)abstract
- We report on optical dispersion and temperature dependence of latching-type magneto-optical properties of heavily Ga-doped bismuth iron garnet films rf-magnetron sputtered onto Gd3Ga5O12 (001) and (111) substrates. At lambda = 677 nm and room temperature, epitaxial Bi3Fe3.34Ga1.66O12 (001) and (111) films show, respectively, saturation Faraday rotation theta(Fsat) = - 0.92 x 10(4) and - 1.05 x 10(4) deg/cm, transmittance T = 0.86 and 0.81, magnetic hysteresis theta(F)-H loop squareness theta(Frem)/theta(Fsat) = 0.84 and 1.0, and coercive field H-c = 6.76 and 24.03 kA/m. Film's Faraday rotation is nicely fitted by molecular field Neel theory in the whole temperature range from T-C = 316 K down to 85 K where theta(Fsat) = - 1.9 x 10(4) deg/cm and H-c = 151.20 kA/m.
|
|
| 4. |
- Johansson, Petter, et al.
(författare)
-
Comparison of Bi3Fe5O12 film giant Faraday rotators grown on (111) and (001) Gd3Ga5O12 single crystals
- 2006
-
Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 515:2, s. 477-480
-
Tidskriftsartikel (refereegranskat)abstract
- Bismuth iron garnet (Bi3Fe5O12, BIG) epitaxial thin films were grown on single crystal (Gd3Ga5O12, GGG) (111) and (001) substrates by rf-magnetron sputtering technique. Processing parameters have been optimized to obtain high deposition rate (2.74 mu m/h) and the surface rms roughness less than 10 nm. X-ray diffraction reveals films epitaxial quality: exclusive (111) or (00 1) orientation with narrow rocking curves and strong in-plane texture. Films possess low optical loss and magneto-optical Faraday rotation (FR) as high as 5 deg/mu m at 677 nm wavelength. Comparative analysis of films grown on (111) and (001) substrates clearly shows significant superiority of BIG/GGG(001) film. For this film, the coercive field similar to 100 Oe appears to be 2.5 times lower while the optical transmission to be 10% higher than that for BIG/GGG(111) film. Enhanced magneto-optical performance of BIG/GGG(001) films relies upon better accommodation of the film-to-substrate mismatch strain through the tetragonal BIG lattice distortions compared to the rhombohedral one in BIG/GGG(111) films.
|
|
| 5. |
|
|
| 6. |
- Kim, Joo-Hyung, et al.
(författare)
-
Wet and dry etching of La-0.67(Sr,Ca)(0.33)MnO3 films on Si.
- 2006
-
Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 515:2, s. 587-590
-
Tidskriftsartikel (refereegranskat)abstract
- We report etching processes of epitaxial La-0.67(Sr,Ca)(0.33)MnO3 (LSCMO) colossal magnetoresistive (CMR) films grown on Bi4Ti3O12/CeO2/YSZ oxide-buffered Si using buffered HF (BHF), potassium hydroxide (KOH) and Ar ion beam etching (IBE) methods. LSCMO films demonstrate high resistivity against the KOH etchant whereas 22 nm/min etching rate was obtained in the BHF with high selectivity over photoresist and Si. Compared to 24 nm/min for Si, Ar IBE yields 16 nni/min etching rate for the LSCMO film and the oxide-buffer layers.
|
|
| 7. |
- Kim, Jang-Yong, et al.
(författare)
-
AgTaO3 and AgNbO3 thin films by pulsed laser deposition
- 2006
-
Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 515:2, s. 615-618
-
Tidskriftsartikel (refereegranskat)abstract
- Silver tantalate AgTaO3 (ATO) and silver niobate AgNbO3 (ANO) films have been grown on to the LaAlO3 (001) and sapphire Al2O3 (0112, r-cut) single crystals by pulsed laser deposition technique from stoichiometric ATO and ANO targets. X-ray diffraction study revealed epitaxial quality of ATO and ANO films on the LaAlO3 (00 1) Whereas on the sapphire r-cut substrate they are preferential (I 10) and (00 1) oriented. To characterize microwave films properties in the range from I to 40 GHz, coplanar line interdigital capacitors were fabricated by photolithography and lift-off technique. ANO film capacitors show superior properties: frequency dispersion was as low as 13%, voltage tunability (40 V, 200 kV/ cm) was about 4.6% at 20 GHz, loss tangent similar to 0.106 at 20 GHz, K-factor-tunability/tan delta from 49% @ 10 GHz to 33% at 40 GHz.
|
|
| 8. |
- Kim, Jang-Yong, et al.
(författare)
-
Niobate-tantalate thin films microwave varactors
- 2006
-
Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 515:2, s. 619-622
-
Tidskriftsartikel (refereegranskat)abstract
- We present comparative characteristics of microwave variable capacitors (varactors) fabricated on Na0.5K0.5NbO3 (NKN), AgTa0.5Nb0.5O3 (ATN) and Ba0.5Sr0.5TiO3 (BST) ferroclectric films sintered by pulsed laser deposition technique. Two port 2 mu m finger gap coplanar waveguide interdigital capacitive (CPWIDC) structures were defined on ferroelectric films surface by a standard lift off technique. Results of the microwave on-wafer tests performed in frequency range 1 to 40 GHz have been examined with a de-embedding technique to extract device characteristics from the measured S-parameters. The frequency dispersion of capacitance was 37%, 4.3%, and 17%; the voltage tunability (200 kV/cm) 22%, 4.7%, and 22% at 20 GHz; loss tangent similar to 0.23, 0.068, and 0.137 at 20 GHz for NKN/Nd:YAlO3, ATN/Al2O3, and BST/Al2O3 films capacitors.
|
|
| 9. |
- Razdolski, I. E., et al.
(författare)
-
Magneto-optical switching in nonlinear all-garnet magnetophotonic crystals
- 2011
-
Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 519:16, s. 5600-5602
-
Tidskriftsartikel (refereegranskat)abstract
- Magnetic field control over the optical switching is demonstrated for a nonlinear all-garnet magnetophotonic crystal with a microcavity (MC) layer possessing both third-order Kerr nonlinearity and magnetooptical activity. A significant enhancement of the effective refractive index of the microcavity layer is observed, that results in the light-induced spectral shift of the MC mode of 2 nm. It is shown that application of the external magnetic field leads to an increase of switching contrast by a factor of two. Possible mechanisms of photorefractive effect involved in the optical switching in all-garnet magnetophotonic crystals are discussed.
|
|
| 10. |
- Östling, Mikael, et al.
(författare)
-
Ferroelectric thin films on silicon carbide for next-generation nonvolatile memory and sensor devices
- 2004
-
Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 469-70, s. 444-449
-
Tidskriftsartikel (refereegranskat)abstract
- Silicon carbide semiconductor technology has emerged as a very good candidate to replace traditional Si devices in special applications such as low loss power switching and high temperature electronics. Ferroelectric thin films exhibit interesting properties for use in semiconductor technology due to the spontaneous polarization which can be switched by an externally applied electric field, and thus are attractive for nonvolatile memory and sensor applications. In this work, the successful realization of ferroelectric thin films in SiC devices is described. The first experimental prototype devices are presented and discussed: A novel integration technique of junction metal-oxide-semiconductor field effect transistors (JMOSFETs) and nonvolatile FETs (NVFETs) on a single 4H-SiC substrate is presented. A constant current control device is based on the SiC JMOSFET. The drain current is effectively controlled and kept constant by a buried junction gate. A new high temperature SiC NVFET with a similar temperature stable current drive is also demonstrated. The nonvolatile memory device, based on the ferroelectric gate stack, was shown to operate up to 300 C with memory effect retained up to 200degreesC.
|
|
