In-field Performance Research Articles

Correlation Between Microstructure and In-Field Performance of Zr-Added REBCO Coated Conductors Made by Advanced MOCVD

In this paper, we present correlation features between critical current density (J c ) and microstructural characteristics of Zr-added (0, 5, and 15 mol.%) REBa 2 Cu 3 O 7-x (REBCO and RE = rare earth) coated conductors fabricated by the novel advanced metal organic chemical vapor deposition technique. The J c along the tape normal (~ B || c-axis) measured by a vibrating sample magnetometer at 30 and 65 K and magnetic flux density range of 0-14 T was used for qualitative comparison of different Zr-added REBCO tapes. It is found that tapes with enhanced in-field J c exhibit a rise of critical current (plateau or fishtail effect) at magnetic flux density 1-8 T and temperatures 65 K. The TEM microstructure analysis indicates that the plateau effect is not the intrinsic property of REBCO matrix but depends on size distribution and density of BaZrO 3 (BZO) self-assembled nanocolumns. Two types of BZO microstructures have been identified: one with uniform BZO diameter 4-7 nm, whereas some films exhibit bottle-shaped BZO nanocolumns with alternating wide and narrow sections, 7-13 and 4-6 nm, respectively. The non-uniform shape and broad size distribution of BZO nanocolumns are correlated to more vortex pinning strength and matching field.

High Performance Coated Conductors Fabricated by UTOC-MOD Process

A new metal organic deposition (MOD) process using precursor solution containing metal trifluoroacetates was developed to improve in-field performance. In this process, the pinning centers of BaMO3 (M: metal elements such as Zr and Hf) materials could be made to be finer by reducing the once coating thickness in the coating and calcination step. This is referred to as the ultra-thin once coating (UTOC)-MOD process. This process improves the in-field performance. The UTOC-MOD process also has the advantage of uniformity of 2-dimensional Jc-distribution, which was determined using a scanning hall-probe microscopy analysis. Improvement of the Jc uniformity was also confirmed based on scribed tapes. A smaller dispersion of the filament-critical current values in the UTOC-MOD tape was determined based on a comparison with the results for obtained by a conventional process. With respect to the mechanical strength, it was established that the dispersion of the delamination strength, which was evaluated using stud-pull equipment, was suppressed. Microstructural analysis revealed that, the UTOC films were pore-free, although large pores are present in the films when conventional MOD is utilized. This difference in the microstructure can be attributed to the aforementioned improvement in the uniformity of the UTOC-MOD films.

Correlation of In-Field Performance of Thick REBCO Films Between 0–14 T and 4.2–77 K

We present results on correlation of in-field performance of 2G-high temperature superconductor (HTS) tapes produced by an advanced metal organic chemical vapor deposition (A-MOCVD) system which enables growth of very thick films (>4 μm) without deterioration in performance with thickness. A set of 175 samples has been measured using a vibrating sample magnetometer (VSM), at temperatures ranging from 4.2 to 77 K and field from 0 to 14 T (B⊥tape). The sample set contains a wide range of characteristics, with Zr doping from 0 to 20 mol.%, film thickness from 1 to over 4 μm and a range of compositions with varying rare earth (RE) excess, as well as varying Ba/Cu stoichiometry. The set has been purposely chosen to include a very wide range of properties, with the goal of identifying common features of REBCO conductors that are independent of the listed variables. The in-field critical current density (Jc) performance has been separated into two factors, temperature dependent self-field Jc and field and temperature dependent retention factor. The results reveal very systematic trends in maximum Jc correlation with temperature and field, which can be utilized both for long length characterization and as a tool for providing insight into pinning mechanisms.

Two-Fold Reduction of <italic>J</italic>cAnisotropy in FeSe0.5Te0.5Films Using Low-Energy Proton Irradiation

High in-field performance and low anisotropy of critical current density J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> are important for superconducting wires/tapes in rotating machine and magnet applications. Here, we report measurements of angular dependence of critical current density J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> in proton-irradiated FeSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> Te <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> (FST) films at magnetic field up to 35 T. We observed two-fold reduction in the J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> anisotropy of FST films at 4.2 K and 15 Tesla magnetic field by irradiation with low-energy (190 keV) proton. In light of recent demonstration of roll-to-roll irradiation process successfully incorporated in the standard 2G HTS long length production wire, low-energy proton irradiation can be a practical solution to enhance the performance of iron-based superconducting wires and tapes, as low-energy ion sources are inexpensive to operate and are readily available commercially.

Superconducting Characteristics of REBCO Coated Conductors With Different Zr Content

In this paper, REBa 2 Cu 3 O 7-δ (RE = rare earth elements, REBCO) coated conductors with different content of self-assembled BaZrO 3 nanorods were grown by metal organic chemical vapor deposition using a roll-to-roll process. Small changes in chemical composition affecting Ba to Cu stoichiometry induce variation in REBCO c-axis lattice parameter and highly affect the self-field J c at 77 K, superconducting transition width (ΔT c ), and in-field performance of coated conductors. While the self-field J c at 77 K in 15 mol.% Zr-added REBCO film (5 MA cm -2 ) was about 28% higher than that in 25 mol.% Zr-added REBCO (3.9 MA cm -2 ), the in-field J c at 30 K, 3 T (B∥c) of the latter was found to be 36% higher than that of the former. The high J c values of 14.9 and 20.3 MA cm -2 at 30 K, 3 T (B∥c) were obtained in coated conductors with the c-axis lattice parameter of 11.74 and 11.76 A in 15 and 25 mol.% Zr-added REBCO films, respectively.

In-field performance and flux pinning mechanism of pulsed laser deposition grown BaSnO3/GdBa2Cu3O7–δ nanocomposite coated conductors by SuperOx

We investigate the field, angle and temperature dependence of the full-width critical current, Ic, of pulsed laser deposition-grown GdBa2Cu3O7 coated conductors with and without additional 6 mol% BaSnO3 (BSO) nanoparticles fabricated by SuperOx. The transport characteristics measured from 7 to 77 K and in applied magnetic fields of up to 6 T are complemented by scanning transmission electron microscopy. This combined approach allows for further insight into the vortex pinning mechanism and helps with understanding the enhancement in Ic. An exemplary scaling of the pinning force curves versus field at different temperatures confirms the additional contribution to pinning by the BSO nanoparticles. Through the temperature dependence of Ic, the weak and strong pinning contributions are determined: strong pinning dominates over almost the entire temperature range especially near the matching field of 1 T, where the largest enhancement in Ic is achieved.

Operator protection in rollover events of articulated narrow track tractors

Articulated steering arrangements, wheeled or tracked, are commonly used on agricultural tractors and earth moving machines. In Continental Europe and Italy in particular, this configuration is typical of narrow track tractors. Despite their widespread use, there is little research that specifically investigates articulated tractor rollover protective structure (ROPS) in-field performance with respect to the ROPS test procedures. The aim was to investigate the relevance of the standardised ROPS test procedures regarding articulation joint mobility. The shortcomings of the procedures concerning the Clearance Zone and ROPS testing are evidenced and discussed. It is a recommendation of this work that an update of the international testing procedure be developed for articulated tractor types. The paper indicates how this may be accomplished and presents remedial measures that can be implemented in the interim until this latter goal is achieved.

BaZrO3 (BZO) nanoparticles as effective pinning centers for YBa2Cu3O7 − δ (YBCO) superconducting thin films

In-field pinning enhancement for high temperature YBCO superconducting thin film is one of the most significant issue towards future high field applications. Various pinning nanostructures have been designed to achieve better superconducting performance. In this work, BaZrO3 (BZO) has been introduced into YBCO for pinning enhancement. Small BZO nanoparticles with diameter of ~ 5 nm have been observed in the YBCO matrix with high film quality. The BZO-YBCO film deposited at 840 °C exhibits the highest transition temperature of 90 K. These small nanoparticles can provide effective pinning centers for the superconducting property enhancement of YBCO. By comparing the critical current density (Jc) performance of YBCO films, with or without incorporating BZO nanoparticles, 840 °C deposited BZO-YBCO exhibits obvious higher Jc values of 7.8 MA/cm2, 26.5 MA/cm2 and 64.5 MA/cm2 at the measured temperatures of 65 K, 40 K and 5 K, respectively. The results indicate an effective approach to achieve enhanced in-field performance of YBCO, by introducing small BZO nanoparticles.

Field Validation of Seed Meter Performance at Varying Seeding Rates and Ground Speeds

Abstract. High planter performance requires achieving near-perfect seed meter performance in the field during planting. In-field meter performance can be impacted by several factors including meter setup, ground speed, seeding rate, planter vibration, and field conditions. A study was conducted to evaluate the field performance of two different seed meters (John Deere Standard and Precision Planting eSet) at varying seeding rates and ground speeds during planting. Study treatments consisted of planting corn at seeding rates of 49,000, 59,000, 69,000, 79,000, and 89,000 seeds ha-1 at four different ground speeds of 6.1, 7.1, 8.2, and 9.5 km h-1. These ground speeds and seeding rates were implemented in a strip-split plot design in the field with seeding rates blocked within the individual ground speed replications. Field tests were performed by uploading a variable-rate seeding prescription map into the planter rate controller and then travelling at the desired ground speed for each planter pass. Field data collection consisted of measuring plant population and plant spacing in the plots separately for each seed meter. Meter performance was evaluated by computing percent skips, multiples, singulation, coefficient of variation (CV), and crop emergence from the field data. Statistical analysis on field data suggested that the percent skips, singulation, CV, and crop emergence were significantly (p&amp;lt;0.05) affected by the seeding rate, and the ground speed did not have any significant (p&amp;gt;0.05) effect on these variables. The percent multiples and CV values also differed significantly (p&amp;lt;0.05) between the John Deere Standard and Precision Planting eSet meter at different ground speed and seeding rate treatments. The percent skips (0.5-3.8%) observed in the field data were, on average, higher than the percent multiples (0.0-1.8%) for both seed meters. The percent skips in general decreased with an increase in the seeding rate whereas no particular trend was observed in the percent multiples. The singulation values varied between 96.0% and 99.4%, and they were not statistically different between the seed meters. The percent CV values increased with an increase in the seeding rate indicating higher variability in plant spacing with increases in the seeding rate. The mean percent emergence for both seed meters ranged from 92.8% to 99.3%, and it was influenced by the seeding rate for the JD Standard meter. A weak association (R2 values between 0.2028 and 0.6587) between the meter performance parameters (percent skips, singulation, and CV) and the meter speed was determined for both seed meters. Results from the study suggested that meter performance was significantly affected by the seeding rate, and the type of seed meter had a significant impact on percent multiples and CV (plant spacing) values attained during planting. Keywords: Field performance, Ground speed, Meter speed, Seed meter, Seeding rate.

A cost effective solution for the deployment of wireless sensor networks

The paper presents a framework for the design and implementation of dynamic sensor networks. The focus is on minimising the costs associated with deploying such networks, while at the same time making available a fully fledged set of functions. This is achieved by leveraging a modular design based on an easily programmable, cost-effective micro-controller that can be interfaced with a set of heterogeneous sensors and wireless technologies. A real-world implementation of the proposed architecture is described. Our preliminary in-field performance measurements show that such a system can manage, with a high degree of precision and in real-time, a sustained rate of data gathered from mobile units.

The onset of dissipation in high-temperature superconductors: flux trap, hysteresis and in-field performance of multifilamentary Bi2Sr2Ca2Cu3O10+x wires

Most widely used practical superconductors (i.e., NbTi, Nb3Sn, Bi2Sr2Ca2Cu3O10+x) are manufactured in a form of multigranular superconducting filaments embedded in a metallic matrix. The performance of these multifilamentary conduits at different physical conditions has been a topic of extended research over the last decades. In this paper we targeted to reveal the precise onset of the electric power dissipation in one of these composite superconductors, Bi2Sr2Ca2Cu3O10+x (so-called 1G HTS wire), at the conditions when external magnetic field, Bappl, is applied in the maximum Lorentz force geometry. As we showed earlier (Talantsev et al 2017 AIP Advances 7 125230), at self-field conditions the transition to the dissipative state in 1G wire upon increasing the transport current, I, despite a multifilamentary wire design sharply steepens at a threshold current, Ic,surfB, at which a simultaneous and abrupt crossover from a non-linear to a linear dependence of the perpendicular component of the local magnetic flux density, Bsurf(I), measured at the conduit surface occurs. We found that the same transition takes place in 1G HTS wire with an applied magnetic field, Bappl, and thus, the definition of critical current in multifilamentary superconductors based on Ic,surfB can be extended to in-field conditions for 1G HTS wire. We also studied effects of the flux trap and magnetic hysteresis upon increasing/cycling the transport current, I, in this conduit superconducting wire.

Pre-crowdsourcing: Predicting wireless propagation with phone-based channel quality measurements

Conducting in-field performance analysis for wireless carrier coverage and capacity is extremely costly in terms of equipment, manpower, and time. At the same time, there is a growing number of opportunities for crowdsourcing of network and sensor information via smart applications, firmware, and cellular standards. These facilities offer carriers feedback about user-perceived wireless channel quality. Crowdsourcing provides the ability to rapidly collect feedback with dense levels of penetration using client smartphones. However, mobile phones often fail to capture the fidelity and high sampling rates of more-advanced equipment (e.g., a channel scanner) used when drive testing for analysis of propagation characteristics. In this work, we quantify the impact of various effects induced by mobile phones when interpreting signal quality such as averaging over multiple samples, imprecise quantization, and non-uniform and/or less frequent channel sampling. To do so, we conduct extensive in-field experiments across heterogeneous devices and environments to empirically characterize the path loss via phone measurements on LTE networks. We find that mobile phones are comparable to advanced equipment in inferred radio propagation, within 0.1 of the calculated path loss exponent by the channel scanner across downtown, single-family, and multi-family residential areas. Lastly, we develop an intuition for the importance crowdsourcing-based propagation prediction by evaluating the effect on coverage estimation when deploying operational networks. For example, we find that even a prediction error of 0.4 for the path loss exponent would cause a 40% redundancy in the covered area or coverage holes for 25% of the targeted area based on whether the error was above or below the actual value, respectively.

Phenotyping from lab to field - tomato lines screened for heat stress using Fv/Fm maintain high fruit yield during thermal stress in the field.

This study aimed to phenotype young tomato (Solanum lycopersicum L.) plants for heat tolerance by measuring Fv/Fm after short-term heat treatments in climate chambers and selected sensitive (low Fv/Fm) and tolerant (high Fv/Fm) cultivars to investigate their in-field performance. Twenty-eight genotypes were phenotyped at 40:28°C for 2 days in climate chambers. A second screening (four high Fv/Fm and four low Fv/Fm genotypes) was conducted for 4 days at 38:28°C, followed by 5 days' recovery (26:20°C). The tolerant genotypes maintained high net photosynthesis (PN) and increased stomatal conductance (gs) at 38°C, allowing better leaf cooling. Sensitive genotypes had lower Fv/Fm and PN at 38°C, and gs increased less than in the tolerant group, reducing leaf cooling. Under controlled conditions, all eight genotypes had the same plant size and pollen viability, but after heat stress, plant size and pollen viability reduced dramatically in the sensitive group. Two tolerant and two sensitive genotypes were grown in the field during a heat wave (38:26°C). Tolerant genotypes accumulated more biomass, had a lower heat injury index and higher fruit yield. To our knowledge, this is the first time screening for heat tolerance by Fv/Fm in climate chambers was verified by a field trial under natural heat stress. The differences after heat stress in controlled environments were comparable to those in yield between tolerant and sensitive groups under heat stress in the field. The results suggest that Fv/Fm is effective for early detection of heat tolerance, and screening seedlings for heat sensitivity can speed crop improvement.

Engineering current density over 5 kA mm−2 at 4.2 K, 14 T in thick film REBCO tapes

We report on remarkably high in-field performance at 4.2 K achieved in >4 μm thick rare earth barium copper oxide (REBCO) samples with Zr addition. Two different samples have been measured independently at Lawrence Berkeley National Laboratory and the National High Magnetic Field Laboratory, achieving critical current densities (Jc) of 12.21 MA cm−2 and 12.32 MA cm−2 at 4.2 K, 14 T (), respectively, which corresponds to equivalent critical current (Ic) values of 2247 and 2119 A/4 mm. These Ic values are about two times higher than the best reported performance of REBCO tapes to date and more than five times higher than the commercial HTS tapes reported in a recent study. The measured Jc values, with a pinning force of ∼1.7 T N m−3 are almost identical to the highest value reported for thin (∼1 μm thick) REBCO at the field and temperature, but extended to very thick (>4 μm) films. This results in an engineering current density (Je) above 5 kA mm−2 at 4.2 K, 14 T, which is more than five times higher than Nb3Sn and nearly four times higher than the highest reported value of all superconductors other than REBCO at this field and temperature. The reported results have been achieved by utilizing an advanced metal organic chemical vapor deposition system. This study demonstrates the remarkable level of in-field performance achievable with REBCO conductors at 4.2 K and strong potential for high-field magnet applications.

High infield performance and critical temperatures in post-annealed MgB2 films

Critical temperatures (Tc) comparable to those of bulk materials were achieved by post-annealing MgB2 thin films grown at a low temperature of 280 °C. The Tc was improved to 36.7 K under annealing conditions of 550 °C for 50 h or more. Under these annealing conditions, a critical current density several tens of times higher at than that of MgB2 wires processed by a powder-in-tube method was achieved at 20 K under 5 T. This is the highest value reported in MgB2 bulk wires and films. Film-based MgB2 is a promising candidate for next-generation MgB2 wires.

Improvement of uniformity of Ic distributions in long REBCO with BMO coated conductors by in-plume PLD method

Long REBa2Cu3OX (REBCO, RE: rare earth element) with BaMO3 (BMO, M: metal) coated conductors have been expected for the industrial and commercial applications at high temperatures in magnetic fields. Especially, the multi-filamentary structure long REBCO with BHO coated conductors are effective for control of the shielding current of coated conductor excited by applied magnetic fields and alternating-current loss. We fabricated long EuBa2Cu3OX (EuBCO) with BaHfO3 (BHO) coated conductors by the IBAD/PLD (conventional PLD) method, which showed the high in-field Ic values. However, in order to realize REBCO with BMO coated conductors for industrial and commercial applications, the much higher uniformity of not only longitudinal and but transversal Ic distributions of long coated conductors with high in-field performance is required. We have tried to develop the long EuBCO with BHO coated conductors by the in-plume (plane-plume) PLD method with high deposition rate of about 24 nm/s to obtain high in-filed performance and low production cost. More recently, we fabricated the 105 m long EuBCO with BHO coated conductors with high uniformity of longitudinal Ic distributions of 2.54 % (STDEV) by the in-plume (plane-plume) PLD method comparing with coated conductors by the conventional PLD method. We measured each Ic value of 8 filaments of 581 µm in width and slot of 20 µm in width for 0.6 m long EuBCO with BHO coated conductors by in-plume (plane-plume) PLD method. Ic distribution in a width direction of the EuBCO with BHO coated conductors by in-plume (plane-plume) PLD method is more uniform than that of the conventional PLD method.

Investigation on the Superconducting Properties of YGBCO/STO/YGBCO Trilayer

Superconductor/insulator/superconductor trilayer structure can be used to increase the superconducting properties in self-field of thick REBa 2 Cu 3 O 7-δ (RE = rare metal) films by inhibiting the thickness effect, as well as improving in-field properties through the interlayer, which acts as a flux pinning interface. The conventional trilayer structure was always prepared symmetrically, namely, the bottom superconducting layer has the same thickness with the top superconducting layer. In this paper, Y 0.5 Gd 0.5 Ba 2 Cu 3 O 7-δ /SrTiO 3 /Y 0.5 Gd 0.5 Ba 2 Cu 3 O 7-δ (YGBCO/STO/Y-GBCO) trilayer films were prepared asymmetrically by pulsed laser deposition on CeO 2 buffered IBAD-MgO tapes, which means the bottom superconducting layer has a different thickness than the top superconducting layer. YGBCO/STO/YGBCO trilayer structure had the same total YGBCO layer thickness of 720 nm and STO interlayer thickness of 80 nm, but a bottom YGBCO superconducting layer of different thickness. Microstructure, surface morphology, and self-field and in-field superconducting properties were systematically investigated. It was found that thicker bottom-layer had almost no internal residual stress, better crystalline quality, and surface morphology, which contributed to better superconducting properties of the YGBCO/STO/YGBCO trilayer sample both under self-field and magnetic field. The phenomenon was explained by the growth model. These results can provide useful information for fabricating trilayer structure with high in-field performance.

Acrylic white paint of industrial sector for cool roofing application: Experimental investigation of summer behavior and aging problem under Mediterranean climate

The paper proposes a complete experimental characterization of an acrylic white paint, widespread in the field of household appliances or automotive sector. This paints has been already studied by means of in-lab tests; results have suggested that it is suitable for cool roof application.In this study, the results of a measurement campaign are discussed; it has been carried out by means of test-room of the University of Sannio, in Benevento city, under Mediterranean climatic conditions starting from the summer 2016 until the summer 2017. In detail, the in-field monitoring concerns: all data for describing indoor and outdoor climatic conditions; the measure of solar reflectance at start and after one year from paint’s application; the indoor and outdoor surface temperatures, the heat flux; optical investigations in visual and infrared field. The proposed paint has been compared with a commercial cool roof product and with a polished aluminum varnish in term of improvement respect to traditional dark bituminous membrane. Also the in-field aging effect is studied to compare degradation of proposed paint and commercial cool paint.Data elaborations bring to interesting conclusions; first of all, the in-field performance of acrylic paint is comparable to cool product and it is better than aluminum paint. Proposed product shows very fast drying, good gloss and appearance, lower application time and positive economic analysis. However, the aging is faster with in-field reduction of solar reflectance of around 20–25%. It could be due to application technique and to adopted product to favor the adhesion. This makes suitable other researches also for evaluate the application of a protective gloss that could assure greater durability than traditional product.

Full-Scale Performance Evaluations of Various Wire-Backed Nonwoven Silt Fence Installation Configurations

Silt fences have long been a key component for controlling construction stormwater runoff; nonetheless, many silt fence installations fail to perform in the field as intended. Silt fences are temporary sediment control measures used to retain sediment by impounding runoff and allowing for sedimentation on-site, while simultaneously discharging stormwater runoff at a controlled rate. This study evaluated the performance of eight alternative configurations of the Alabama Department of Transportation (ALDOT) standard wire-backed, nonwoven silt fence. Standard installation parameters associated with the ALDOT silt fence include (1) 32-in. (81.3-cm) high fence, (2) 0.95 lb/ft (1.4 kg/m) support T-post, and (3) 10 ft (3.0 m) T-post spacing. Throughout the series of configurations tested, these standard parameters were varied individually and jointly in efforts to improve overall performance. Variations to the standard parameters include (1) 24-in. (61.0-cm) high fence, (2) 1.25 lb/ft (1.9 kg/m) support T-post, (3) 5 ft (1.5 m) T-post spacing, and (4) trench offsetting. Performance analyses were conducted on each configuration and results were evaluated to determine the best overall configuration to enhance the in-field performance of the ALDOT silt fence. Ultimately, the offset 24 in. (61.0 cm) fence with 1.25 lb/ft (1.9 kg/m) T-post spaced 5 ft (1.5 m) on-center resulted in the best overall improvement, retaining an average of 93% of sediment and deflection of only 0.18 ft (0.004 m) over the course of three simulated storm events.

Control of artificial pinning centers in REBCO coated conductors derived from the trifluoroacetate metal-organic deposition process

The metal-organic deposition (MOD) process using metal trifluoroacetate salts (TFA) has the advantages of low-cost and high-scalability for the fabrication of REBa2Cu3Oy (REBCO, RE: rare earth elements) superconducting coated conductors (CCs) with high critical current density, in principle, because of its non-vacuum process. For the magnetic applications of CCs such as motors, magnetic resonance imaging and superconducting magnetic energy storage, further improvement of superconducting performance under magnetic fields is required. However, the in-field superconducting performance of REBCO CCs derived from the TFA-MOD process had been inferior to those derived from the vapor-phase process. In order to improve the in-field performance, the size control of the artificial pinning centers has been known as an effective way. In the early stage, the BaZrO3 (BZO) material, which was one of the effective materials in the CCs by the vapor-phase process, was also introduced in the TFA-MOD-derived CCs. The unique feature of the BZO material in the TFA-MOD process is the shape. The BZO in the TFA-MOD process formed the particle shape, although in the vapor-phase process it has a rod shape with a long axis elongating along the thickness direction. In addition, a special heat treatment for refining the BZO particles was developed, which is called the ‘interim heat treatment’. This heating profile made the in-field characteristics higher, although they were still lower than those of the vapor-phase process. Then, the new MOD process including ‘ultra-thin once coating’ was recently developed for further refinement of the BZO particles. The characteristics of the new TFA-MOD-derived CCs in magnetic fields have become compatible with those of the CCs derived from the vapor-phase process.