Oral session, A-3, August 30, 2017 (North 2F, room 28, Bulk thin films growth Microstructures I)

Chairs: Petre BADICA and Tomoya HORIDE, 13.45-15.25

4 presentations:
1 keynote (A3-K30-018 – J H Durell) – 35 min
2 invited (A3-130-019 – X Yao; A3-130-020 J Gazquez) – 25 min
1 oral (A3-O30-021- S Horii) – 15 min

Presentations introduced by P. Badica

Keynote presentation: The challenge of high filed bulk superconductors, J. H. Durell discussed the problems associated with melt textured HTS bulk superconductors especially regarding poor mechanical strength of HTS. It was emphasized the necessity to improve the mechanical properties of the materials (e.g. by metal fibers additives such as Ta) or by innovative engineering solutions using compressing metal rings to help keeping the integrity of the magnetically loaded bulk. Questions were about different possibilities of clamping and about the limitations imposed by size.

Invited presentation 1: The artificial control of film microstructures in LPE-processes YBCO by tuning solute supersaturation state, X. Yao introduced different aspects of the crystal growth of REBa2Cu3O7 superconductors (especially by liquid phase epitaxy method). The possibilities to control growth and quality of materials were discussed (e.g. by using non-stroichiometric compositions, or the appropriate conditions of cooling based on thermodynamic aspects of the supersaturation). Questions were about film thickness and spiral growth mechanism.

Attendance: good – about 20 persons

Schedule: according to the program

Atmosphere: relaxed, friendly, collaborative

Symposium C-5: Frontier of Nano-Materials Based on Advanced Plasma Technologies

A Challenge for Future Carbon Devices by Advanced Plasma Nano-Processes

Masaru Hori of Nagoya University, Japan, gave a fantastic keynote lecture in the oral session of Symposium C-5 in the morning session on August 30. He has investigated advanced plasmas as a synthesis method, the growth mechanism, control of structure, and applications for nano-carbons. First, he presented fabrication of the tough fuel cell devices with carbon nanowalls (CNWs), where Pt nanoparticles were supported on CNWs by super critical CVD after the growth of CNWs. Second, he explained that the triple phase plasma employing the ethanol alcohol showed the high speed and high quality nano graphene synthesis for a high performance of fuel cell device. Then, he concluded that nano carbons, especially CNWs, had a great potential as a key material for future industrial and medical applications.

Fabrication of High-Mobility Amorphous In2O3:Sn Films by RF Magnetron Sputtering with Impurity-Mediated Amorphization Method

Naho Itagaki of Kyushu University, Japan, gave an excellent keynote lecture in the oral session of Symposium C-5 in the afternoon session on August 30. She proposed an impurity mediated amorphization (IMA) method, where the impurity was introduced to the conventional control parameters (temperature and pressure) for crystal growth. She explained that high mobility (> 50 cm2/Vs) and nanocrystal-free a-ITO films have been obtained, and the a-ITO films were grown even at higher temperature than the crystallization temperature (150°C) of In2O3. In addition, the a-ITO films fabricated via IMA showed high thermal stability, which means that the amorphous structure was maintained even after they were annealed at 300°C.


Keynote lecture scene by Prof. Hori.

Keynote lecture scene by Prof. Itagaki.

Sômiya Award ceremony and presentation

This IUMRS-SOMIYA Award is named in honor of Professor Shigeyuki Sômiya. IUMRS manages this award program for encouragement of active international collaboration in materials science field. In this time, five active teams applied to this selection.

Past two award winners examined all application forms on the basis of following three criteria.

The team to be honored must have collaborated across at least two continents some time during the last decade.

The collaborative work must be of the highest quality and well recognized by the international materials community.

The impact on technology or society is also a major factor.

The award commission chair Professor Robert Chang officially approved examination reports.

Then IUMRS-SOMIYA Award 2017 goes to following collaborative work and team.

Award winning work;

Semiconductor Nanowires: Growth, Characterization, Processing and Optoelectronic Devices

Team leader: Professor Chennupati Jagadish (Australian National University, Australia)

Professor Leigh M. Smith (University of Cincinnati, USA)
Professor Michael B. Johnston (Oxford University, UK)
Professor Jin Zou (University of Queensland, Australia)
Professor Antonio Polimeni (University of Rome La Sapienza, Italy)

On 30
th August from 5 pm, the award ceremony was organized at Yoshida Campus.

Photographs are beautiful smile of winners and award presenter.

Left: award presenter Professor Jim Williams
Right: Team leader Professor Chennupati Jagadish



Left: award presenter Professor Jim Williams
Right: Team member Professor Antonio Polimeni

Symposium A-3:Session Pinning IV , August 29th


Invited talk given by Alexey V Pan from Institute for Superconducting and Electronic Materials, University of Wollongong.

The first part of the talk was about magnetic measurements performed with a VSM system where it could be observed that the Jc performance of a superconducting sample was strongly dependent on the measurement frequency.
The second part talk was about the design of different microstructures (with many different shape, distribution and sizes) patterned on superconducting films. Samples were mainly characterized by means of magnetic measurements and magneto-optical imaging. Nice correlation of superconducting properties could be obtained depending on the patterning performed. Ratchet effects were studied in samples with asymmetric patterns. Both theoretical calculations and measurements show differences in the critical current density when inverting the direction of the current.


Invited talk given by Petriina Paturi from Wihuri Physical Laboratory, University of Turku.
The talk was about theoretical calculation of flux pinning effects in YBCO thin films with artificial pinning sites (nano-rods, nano-particles).
The first part of the talk was about simulations of angular Jc measurements performed on samples with different artificial pinning centre landscape. The samples were grown alternating layers of different thicknesses with rods and plane YBCO in order to change the length of nanorods. Experimental angular Jc measurements show that long nano-rods produce strong c-axis peak while short nano-rods could not. The simulations performed could nicely explain the experimental data.
The second part of the talk was about the analysis of alpha values and pinning force curves in YBCO samples with different nano-structures, correlating the experimental results with simulations.


Oral talk given by Gianluca de Marzi from ENEA C. R. Frascati, Technical Unit for Nuclear Fusion-FSN (Rome), Italy
The talk was about ac measurements on YBCO thin films with BNTO and BNTO+YO nanoparticles. The activation energy of different samples was evaluated from ac susceptibility measurements performed at different frequency and different conditions of ac and dc magnetic field. From those measurements the activation energy as a function of the magnetic field and critical current density could be obtained and correlated with the critical current density performance of different samples.

* The session finished 15 minutes late since we had some technical problems with the projection of the last talk and we had to change the computer.

Symposium A-3:Session Pinning III , August 29th

-Talk 1 A3-129-005 by G. Celentano (invited)

PLD YBCO thin films with improved pinning by doping tamtalates and niobates (BaYTaO6 and BYNnO6) in extended temperature and high H field via double perovskite (sponsored  by Euro tapes and Euro fusion programs)

Several doping schemes of single and double APCs were explored and the superconducting properties, especially Jc were compared.

For example, three specific schemes were compared:

  1. BYTO at 5 at%, d=8nm), 1D(5nm, H*~5.2 T) +2D(stacking faults?)
  2. 5at%+BYTO2.5at% (d=8nm), 1D(5nm, H*~5.2 T) +2D(stacking faults?)-best Jc-H in few-10T, still see both Jc peaks at both H//c, and ab
  3. 5at%+BYTO2.5at%+3.75at% Y2O3, 1D(10 nm, H*~1.9 T), many 3D

Also, varied the PLD repetition rates were explored: from 1Hz (12 nm, 1.1T) to 5Hz (7nm, H*~2T), to 10 Hz (5nm, 5.2 T)

-Talk 2 A3-129-006 by L. Civale for B. Bairov (invited)

Talk’s primary focus was on the Rho and Jc measurements in pulsed H field at LANL, which has facility that  can reach 65T up to 100 T ( as a part of the Nat. High Mag. Field Lab) in few to tens of ms time frame  in He4 and He3.  Measurement can be operated at fixed theta, pulsed H at different Ts, or fixed T, pulsed field at different theta’s

Measurement on iron-based supercond, two band model SUST 2014, 27 by Maiorov. Mele, et al and on the YBCO with DD (similar to the N Mat. Paper in 2011), BZO NPs in CSD film increases the B_irr significantly

-Talk 3 A3-129-007 by T. Izumi (invited)

Control in-field performance by modifying microstructure in cc, 1D, 2D and 3D APCs, morphologies depending on the process (PLD, MOD, MOCVD), conditions (T, PO2, composition)and materials of APCs.

In situ method PLD-1D APCs, while ex situ one CSD, 3D APCs of the same dopants (BZO)

Super saturation at the synthesis temperature leads to formation of  BZO NPs in CSD process. PLD multilayer growth to generate layered (2D) APCs in ab-plane (BHO) in BHO/GdBCO (Yoshida), by spinning thinner precursor (30 nm) vs old 170 nm, found smaller BZO NPs ~ 10-12nm, in contrast to 16 nm, radius of NP lambda=2D/V, V-growth velocity, D-diffusion speed.


Symposium B-4: Congratulations on winning the Langmuir Award and Soft Matter Award!!

In our symposium, active researchers in soft matter science have gotten together from all over the world (more than 10 countries) and have made active discussion of the up-to-date results on soft matter science. “Langmuir Award” and “Soft Matter Award” were provided to our symposium by courtesy of the ACS publications and Royal Society for Chemistry. The presentations made by young researchers were judged by the aid of invited speakers of our symposium and the symposium organizers have elected the five award winners. The winners are listed as below:

Langmuir Award

B4-P29-009 Yuki OHARA (University of Hyogo, Japan)

“Incorporation of and release behavior of guest molecules by pH-responsive polyion complex vesicles”

B4-P29-021 Ko MATSUKAWA (The University of Tokyo, Japan)

“Preparation of hydrogel which has comb-type polymer network only in the surface region”

Soft Matter Award

B4-O29-012 NienTing HSIEH (Chung Yuan Christian University, Taiwan)

“Molecular design of a dual-functional quaternary amine copolymer for bacterial reversible self-cleaning control via zwitterionic counterion activation”

B4-P29-003 Nozomi ARAI (Kyoto University, Japan)

“Direct observation and modeling of attachment behavior of colloid particles on a bubble surface”

B4-P29-005 Yoji YAMASHITA (Osaka City University, Japan)

“Synthesis of curable hyperbranched polymers containing dense degradable groups and their application to degradable cured materials”


Group photo of the B-4 Symposium.

Mr. Nozomi ARAI (Kyoto University), the winner of the Soft Matter Award


Report „Devices / Heavy Fermion II“ Aug. 29, second part

Kenji Ishida reported in his invited talk on NMR and NQR studies on U-based ferromagnetic superconductors. He showed that in UCoGe a spin triplett superconducting state is induced by fluctuations. This is a new mechanism to suppress superconductivity.

A collaboration of groups from Japan and a group of Vietnam develops a scanning LTS-SQUID vector microscope with three orthogonal pick-up loops on a tip cooled by a commercial GM cryocooler. The sensors were tested and high spatial resolution demonstrated.

The figure shows the pick-up loops (left) and a trapped vortex structure measured by the new SQUID vector sensors within a commercial SSM (right).

Report on A-3 sessions of August 29

Matsumoto: Interesting TDGL simulations of Jc and comparison to experiment. It is reported experimental Jc measurements on BHO doped GdBCO with different level of doping. Best pinning force density Fp at 10 K was achieved on 20:1 volume fraction. The analysis of temperature behavior Jc(T) with Griessen’s model is reported.

Questions: Is the simulation 3D? No. How many pinning sites can be added to the simulation? What is the meaning of the background pins at high field? Difference of delta-l and delta-Tc pinning? How is Jc determined in the simulation?

Yoshida: SmBCO + BaHfO3 coated conductors. Low-T growth technique (750 C vs 960 C) with seed layer (150 C less than without). Rods are thinner (7 nm vs 13.5 nm), B_phi is larger. High rate leads to small pinning sites (similarly as in previous presentations).

High speed growth technique in a reel-to-reel deposition systems up to 100 Hz. No degradation of Jc reported. No clear which is the actual film growth rate.

Questions: How are the inclination angles defined? What is the effect of strain in growth of nanocolumns? What is the Ic of the sample? (from patterned sample) What is the growth rate in “high growth rate”-films?

How is the substrate temp measured? 960 C is a lot! (didn’t ask this, because of lack of time)

Erbe: ReBCO + BHO on TFA-MOD on STO and CeO2-buffered CC. Re = Gd, higher Tc, should have wider deposition parameters. Result: Narrow process parameters, otherwise impurities (on STO). On STO optimal deposition conditions are: T = 810 °C and P(O2) 100 – 50 ppm. On metal optimal t_sub is 20 C lower (we’ve seen this also on PLD films) due to the reaction with CeO2 seed layer (BaCeO3 forms). Pores in films on meta.

Questions: What about the in-plane texture? Good in-plane texture. Optimal temperature difference STO / CC. Thickness of the films: 250-300 nm.

Jha: Surface modified target approach to enhance Jc, Y211 dopant as segment of target. Nano dots formed into YBCO matrix. Jc measurements carried out at 77 and 65 K. Dip in the Jc(theta) near ab-plane. Otherwise almost isotropic. Theory from Mishec SUSt 28. Planar defects cause a dip in ab-planes. For further work doping with other rare earths RE211 phases will be studied.

Questions: Could this promote substitution of rare earth ion of dopant on superconductor? A: yes, but the final effect of this cannot be predicted in advance.

van der Beek: edge disorder and rough flux front. Flux noise in rf antennas. MO-visualization. Seen also in Nb. And in other elastic media (paper, ink on paper etc). Calculate correlations in space and time. Universality classes vary between different superconducting materials. Controlled disorder, irradiated with heavy ions.

Questions: How do the flux avalanches in MgB2 relate to this? Not really definite yet.

Plenary 3 : Topological Quasiparticles: Magnetic Skyrmions

Axel Hoffmann, Materials Science Division, Argonne National Laboratory

In his plenary lecture Axel Hoffmann discussed new magnetically ordered structures, which recently have gained much attention due to their potential for low-energy applications.  These magnetic structures are called magnetic skyrmions and this name is derived from the theoretical physicist Tony Skyrme, who originally developed in the 1960’s a theoretical model describing nuclear particles as topological solitons within a vector field.  But similar structures can also form in magnetically ordered materials.  Interestingly, due to their distinct topology these magnetic skyrmions can behave like individual stable particles.

They were first discovered about a decade ago in special magnetic materials at low temperatures, but the work from Axel Hoffmann and his colleagues showed that they can be also stabilized at room temperature in magnetic multilayers of materials that are commonly used for magnetoelectronic applications.  At the same time these magnetic skyrmions can be easily manipulated with even very low electric currents, which makes them of interest for data storage and processing applications.

During his presentation Axel Hoffmann also showed two interesting basic physics concepts.  First he showed that magnetic skyrmions can be formed by using inhomogeneous electric currents.  This process is strikingly similar to common phenomena in surface tension driven fluid flows, such as the formation of soap bubbles by blowing through a suspended soap film.  Second he showed that the twirling magnetic structure of magnetic skyrmions results in “curved” trajectories.  The physics behind this skyrmion Hall effect is very similar to the motion of curveball in baseball or soccer, where the rotation of the ball results in a change of trajectory to confuse the batter or goalkeeper.  This shows that the investigation of magnetic skyrmions is not only fascinating because of their prospect for novel applications, but that their distinct topology also provides new interesting fundamental physical phenomena.

Axel Hoffmann always gives very interesting and valuable presentations, and his lighthearted approach, makes his talks very engaging.  Thus his Plenary Talk offered both an academic and peaceful atmosphere to audience.  As part of his Talk he presented a brief video showing how the Brazilian soccer player Roberto Carlos used a curved ball to leave the French goalkeeper confused.  This gave the audience an easy understanding for difficult physics delivered with humor.  But of course the question arises, whether “the twirling magnetic structure of magnetic skyrmions moving on curved trajectories” confused anybody?  Fortunately Axel Hoffmann addressed any remaining confusion well during the questions and answers.

PL.2 Helical Polymers as Unique Chiral Materials Professor Eiji Yashima (Nagoya University, Japan)

The helix is ubiquitous in nature, and one of the prevalent structural motifs for biological polymers, playing key roles in their sophisticated functions. Professor Yashima showed unique polymers consisting of preferred-handed helical conformation induced by chiral dopants.  Generally, the polymer lost preferred-handed helical structure when the chiral dopant was removed from the system.  He showed novel helical polymer which remain the preferred-handed helical structure even after removal chiral dopant using specific poly acetylene with well-established side chains.  This memory effect can be utilized for production of separation materials for chiral chemicals and drugs.

Prof. Yashima summarized helicity induction and memory strategy which has a remarkable advantage from a practical viewpoint.  Various examples on the direct observations of helical structures of synthetic helical polymers by atomic force microscopy (AFM) was presented. A series of double and/or multi helices composed of different components and sequences that exhibit specific functions, such as chiral recognition and anisotropic spring-like motion was also introduced with very impressive images.