ES2259919B1 - PREPARATION OF ANHYDING METALORGANIC PRECURSORS AND THEIR USE FOR THE DEPOSITION AND GROWTH OF LAYERS AND SUPERCONDUCTOR RIBBONS. - Google Patents

Abstract

Preparation of anhydrous metalorganic precursors and their use for the deposition and growth of superconducting layers and tapes. The present invention relates to a new method of producing metalorganic oxide precursors by means of anhydride attack of those same starting oxides. Its use is very general and valid for preparing oxide sheets of all types (ferroelectric, ferromagnetic, piezoelectric, etc.). It also refers to a production process of YBCO anhydrous metalorganic precursors and its application in a process for manufacturing layers of said superconducting material. The low water content of the precursors prepared according to the process of the present invention makes it possible to eliminate intermediate purification steps. The new precursors allow to reduce the time of pyrolysis for its decomposition, so that the productivity in the production of superconducting layers and tapes is significantly increased while maintaining its quality and performance.

Description

Preparation of metalorganic precursors anhydrous and its use for the deposition and growth of layers and tapes superconductors

Technical sector

The present invention relates to a new Production process of metalorganic oxide precursors by way of attack with anhydride of those same starting oxides. Its use is very general and valid to prepare oxides sheets of all types (ferroelectric, ferromagnetic, piezoelectric, etc.), although in the present invention it is applied to the manufacture of superconducting oxides.

The objects of the present invention are of Special relevance in the following sectors:

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Sector Chemist: Metalorganic precursors.

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Sector Ceramic-metallurgical: Deposition and growth of ceramic coatings on metal substrates.

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Sector Energy: Improvement of the efficiency of electrical equipment existing and development of new electrical equipment of power.

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Sector Biomedicine and Pharmaceutical: New diagnostic equipment and new NMR spectrometers for molecular design.

State of the art

Metal oxides are compounds of great interest due to its wide field of application that goes from the superconductivity at high temperatures, ferromagnetism, piezoelectricity until semiconductivity. The preparation of themselves by a low cost method such as the deposition of solutions of chemical precursors has made them have studied a great number of these for possible application in obtaining oxides Depending on the final objective to be achieved, it has started from chemical precursors such as organometallic molecules (acetates  trifluoroacetates, acetylacetonates, ethylhexanoates, alkoxides), metal salts (nitrates, iodides) and polymers. Mixed oxides they can be obtained by mixing similar precursors in a solvent common before pyrolysis.

The preparation of superconducting oxides is a field of great interest due to the wide variety of applications of them, ranging from diagnostic imaging in Medicine (Nuclear Magnetic Resonance) until its numerous applications in the Energy sector (eg superconducting magnets for the Energy storage).

There are two types of superconducting oxides, those based on Bismuth (Bi_ {2} Ca_ {2} Sr_ {2} Cu 3 O_ {10}) and those of Ytrio (YBa_ {2}
Cu_ {3} O_ {7}), however due to its better properties, from the point of view of stability and critical current density, even under a magnetic field, the latter are the ones that have aroused the greatest interest.

At present it is already working in the obtaining superconducting tapes called second generation that typically consist of a metal substrate, one or several thin epitaxial buffer sheets that protect chemically to the substrate, and a thin epitaxial sheet superconductor of YBa_ {2} Cu_ {O} {7} (YBCO).

There are different methods for preparation of superconductors based on Ytrio oxides among them We can cite the laser deposition (PLD), spraying by radiofrequency, liquid phase epitaxy or evaporation by electron beam Among all of them the deposition of the plates thin using chemical solutions has deserved in the In recent times, special attention since it avoids the use of expensive vacuum techniques and allows the preparation of oxides Superconductors with low cost.

The use as metalorganic precursors of the corresponding Ytrio, Copper and Barium acetates gives rise to low performance superconducting oxides, normally due to Barium carbonate formation during pyrolysis. How alternative, mostly trifluoroacetates have been used metallic as starting products mainly due to the simplicity of the methods of preparation thereof, without However, there are some published studies that start from others precursors such as halides or some fluoride-free precursors that they are normally pivalates of the corresponding metals.

For the preparation of the precursor mixture, commercial acetates are normally used, which, in aqueous solution and in the presence of trifluoroacetic acid, generate the corresponding trifluoroacetates (T. Araki, K. Yamagiwa, I. Hirabayashi. US Pat. No. 6,586,042 ( 2003), "Method of preparing oxide superconductor with purified mixed metal trifluoroacetate"). Under these conditions the compounds formed require subsequent purifications in order to remove water (reaction solvent) and possible secondary products (acetic acid) to give rise to the mixture of metal trifluoroacetates with sufficient purity for, after pyrolysis and growth, give rise to superconducting material with good performance. Among the methods of preparation based on acetates we can also mention those used by Gupta et al . (A. Gupta, R. Jagannathan, EI Cooper, EA Giess, JI Landman, BW Hussey, "Superconducting oxide films with high transition temperature prepared from metal trifluoroacetate precursors" Appl. Phys. Let . 52, 1988, 2077) or the group by McIntyre and Cima (PC McIntyre, MJ Cima, and MF Ng, "Metalorganic deposition of high-J Ba YCu O thin films from trifluoroacetate precursors onto (100) SrTiO," J. Appl. Phys ., 68, 1990, 4183) .

Also, the deposition methodology of thin sheets of YBCO using TFA salts in the form of chemical solution has been used by other authors on substrates monocrystalline (J. Smith, M.J. Cima, International Patent Classification HO1L 39/24, International Publication Number WO 98/58415, "Controlled Conversion Of Metal Oxyfluorides Into Superconducting Oxides ") or on sheet metal substrates buffer deposited by vacuum techniques.

An aspect of the use of this technique which is also of great relevance, from the point of manufacture of great lengths of tapes, is to achieve minimize the time required to perform the pyrolysis, that is the decomposition of metalorganic precursors. In a process of continuous manufacturing said time will determine productivity (meters per hour) of tape that can be achieved.

The precursors used to date they require very long pyrolysis times if they want to keep Good superconducting performance. In order to reduce said pyrolysis time, other authors have used additives in the dissolution of trifluoroacetates that reduce this time, for example diethanolamine (DEA) (J.T. Dawley, P.G. Clem, T.J. Boyle, L.M. Ottley, D.L. Overmyer, M.P. Siegal, "Rapid processing method for solution deposited YBa_ {2} Cu_ {3} O_ {7- \ delta} thin film ", Physica C, 402, 2004, 143). Such additives, however modify the properties that control crystallization and superconducting benefits. It is therefore desirable to reduce the pyrolysis time without introducing limitations on the performance of manufactured superconductors.

Descriptive of the invention - Brief description

An object of the present invention relates to the production of metalorganic oxide precursors by way of anhydride attack of those same starting oxides.

Another object of the present invention relates to to the production of anhydrous metallurgical material consisting of Y, Ba and Cu trifluoroacetates from anhydride attack YBCO trifluoroacetic acid.

Another object of the present invention relates to to the materials obtained through the production processes of Metalorganic precursors claimed in it.

Finally, another object of the present invention is to provide an improved new process to obtain sheets of superconducting oxides using deposition and decomposition of metallic trifluoroacetates prepared under anhydrous conditions, according to the procedure claimed above.

To date precursor preparation Metalorganics for the production of oxides implies the realization of numerous intermediate purification processes that are necessary to get good benefits. The use of Anhydrous solutions avoid much of these intermediate steps getting very good results in the final oxides of a simplified form. The procedure for obtaining material anhydrous metalorganic from its oxides of the present The invention comprises the following steps:

to)

oxide powder solution in:

i)

a anhydride corresponding to an organic acid capable of dissolving said oxide,

ii)

a small amount of organic acid from point i) that acts as reaction catalyst and

iii)

acetone as solvent,

b)

heating the mixture in atmosphere inert,

C)

filtration of the resulting suspension at room temperature,

d)

evaporation of the resulting mixture with a rotary evaporator under reduced pressure,

and)

solid waste redisolution as well obtained, and

F)

optionally, storage of trifluoroacetates thus obtained in vials in atmosphere inert.

In particular, step a) may consist of dissolving the oxide powder in trifluoroacetic anhydride ((CF 3 CO) 2
O), a small amount of trifluoroacetic acid (CF 3 COOH) as reaction catalyst and acetone as solvent.

The use of anhydrous solutions for preparation of metalorganic precursors for obtaining Superconducting oxides avoid much of the processes purification intermediates currently required, resulting in final oxides with very good performance (various thicknesses hundreds of nanometers and current densities of 1-5 MA / cm2) in a simplified way.

The properties of sheets and tapes obtained with the new anhydrous metalorganic precursors are seen improved compared to previously used methods due to that these have a higher purity, in particular the content in solution water is practically null (below the limit of detection using the Karl-Fischer method (1 ppm)). On the other hand a great practical advantage of the new The methodology developed is that this level of purity directly, that is to say without realization being necessary of long and expensive solutions purification processes. An additional advantage of the new precursors obtained is refers to the possibility of considerably reducing the time required in the process of decomposition of precursors deposited, with respect to those that have been used previously, maintaining however a high quality of the layers. The advantage of said reduction in decomposition time is to allow increase the production speed of superconducting tapes in The processes in continuous.

The method used to produce sheets epitaxial superconductors on ceramic substrates monocrystalline or metal tapes containing buffer sheets epitaxials allow to obtain critical current densities J_ {c} up to 4,000,000 A / cm2 at 77 K in null magnetic field.

- Detailed description

An object of the present invention relates to the production of anhydrous metalorganic precursors from its oxides by way of attack with anhydride of those same oxides of departure. Figure 1 shows the flow chart of the processes that must be followed for solution synthesis precursor of a generic oxide. These steps are the following:

to)

oxide powder solution in:

i)

a anhydride corresponding to an organic acid capable of dissolving said oxide,

ii)

a small amount of organic acid from point i) that acts as reaction catalyst, and

iii)

acetone as solvent,

b)

heating the mixture in atmosphere inert,

C)

filtration of the resulting suspension at room temperature,

d)

evaporation of the resulting mixture with a rotary evaporator under reduced pressure,

and)

solid waste redisolution as well obtained, and

F)

optionally, storage of trifluoroacetates thus obtained in vials in atmosphere inert.

In particular, step a) may consist of dissolving the oxide powder in trifluoroacetic anhydride ((CF 3 CO) 2
O), a small amount of trifluoroacetic acid (CF 3 COOH) as reaction catalyst and acetone as solvent.

There are different chemical precursors that can be used for the preparation of metalorganic solutions that can be deposited in the substrate for the subsequent growth of a crystalline phase These precursors are the ones that are usually used in the so-called sol-gel methodologies or metalorganic decomposition. In the first case these precursors they are normally alkoxides, soluble in alcohols and sensitive to ambient humidity, therefore they must be handled throughout the Inert atmosphere process. In the second case they are used carboxylates (acetates, hexanoates) or pentadionates (acetylacetone) soluble in different organic solvents and less sensitive to environmental humidity. They can also be used hybrid solutions with precursors belonging to both groups

In the present invention it has been based on Trifluoroacetates prepared under anhydrous conditions using for this, trifluoroacetic anhydride ((CF 3 CO) 2 O) as a starting reagent instead of trifluoroacetic acid (CF 3 COOH). The lower reactivity of anhydrides makes necessary to use a small amount of acid trifluoroacetic acid (5% by volume) as the reaction catalyst. Although in the embodiments of the present invention has particularized the use of anhydride and trifluoroacetic acid, in in general any anhydride corresponding to another can be used organic acid that dissolves rust powders.

In a spherical flask provided with a Dimroth refrigerant and agitation oxide oxide powder is introduced MM'O, excess trifluoroacetic anhydride and trifuoroacetic acid (5% by volume) as catalyst, using acetone as solvent. Be  heats the mixture at a temperature between 45 ° C and 50 ° C for a period of time between 50 and 80 hours in an inert atmosphere. The resulting suspension is then filtered and evaporated to a vacuum between 0.6 and 2 mbar, heating up to 75ºC or 80ºC. He solid residue thus obtained is redissolved in acetone or methanol until the desired concentration The solution of M and M 'trifuoroacetates The resulting anhydrous is stored in vials in an inert atmosphere.

These materials, with a low water content in the solution, prepared according to the procedure just describe, constitute another object of the present invention. Too The use of said materials for the purpose of the present invention is deposition and growth of layers and ribbons of oxides, such as ferroelectric, ferromagnetic and piezoelectric oxides

Another object of the present invention relates to to the production of consistent anhydrous metalorganic precursors in trifluoroacetates of Y, Ba and Cu from YBCO via anhydride attack of that same starting oxide. In Figure 2 the flow chart of the processes to be followed is shown for the synthesis of said precursor solution. The steps are the following:

to)

YBCO powder solution in trifluoroacetic anhydride ((CF 3 CO) 2 O), a small amount of trifluoroacetic acid (CF 3 COOH) as reaction catalyst and acetone as solvent,

b)

heating the mixture in atmosphere inert,

C)

filtration of the resulting suspension at room temperature,

d)

evaporation of the resulting mixture with a rotary evaporator under reduced pressure,

and)

solid waste redisolution as well obtained, and

F)

optionally, storage of trifluoroacetates thus obtained in vials in atmosphere inert.

In the present invention it has been based on Trifluoroacetates prepared under anhydrous conditions using for this, trifluoroacetic anhydride ((CF 3 CO) 2 O) as a starting reagent instead of trifluoroacetic acid (CF 3 COOH). The lower reactivity of anhydrides makes necessary to use a small amount of acid trifluoroacetic acid (5% by volume) as the reaction catalyst. Although in the embodiments of the present invention has particularized the use of anhydride and trifluoroacetic acid, in in general any anhydride corresponding to another can be used organic acid that dissolves YBCO powders.

For the preparation of the chemical solution, Insert into a spherical flask fitted with a Dimroth refrigerant and magnetic stirring YBCO oxide powder, anhydride excess trifluoroacetic acid and trifuoroacetic acid as catalyst, using acetone as solvent. 5% by volume of the substance catalyst gives optimal results, although this amount could vary. The mixture is heated to a temperature between 45 ° C and 50 ° C for a period of 50 to 80 hours in inert atmosphere Heating at 50 ° C for 72 hours in Argon's atmosphere provides optimal results. Then it filter the resulting suspension with 0.45 µm filters and evaporates under vacuum (0.6 to 2 mbar) by heating up to a range of temperatures from 75ºC to 80ºC. The solid residue thus obtained is redissolve in acetone or methanol to the desired concentration. The solution of anhydrous Ytrio, Barium and Copper trifuoroacetates is Store in vials in an inert atmosphere.

Such materials, prepared according to procedure described above, which results solutions with a very low water content (less than 1 ppm), they constitute another object of the present invention. It is also a object of the present invention the use of these materials as anhydrous metalorganic precursors for deposition and growth of superconducting layers and tapes.

Another object of the present invention is constitutes the procedure for obtaining superconducting material in the form of a layer characterized by the use of chemical solutions anhydrous Trifluoroacetate type described above, for Superconducting foil reservoir, comprising the following Steps.

Deposition of chemical solutions

The deposition of the solution in the substrate Metallic can be done by any method that allows control the thickness of the sheet obtained while allowing get a homogeneous thickness. Preferred methods, for their simplicity, they are "spin coating" and "dip coating" in the which parameters such as rotation speed and acceleration (spin coating) and travel speed (dip coating). The first method is best suited to trials in small substrates while the second case is best suited to continuous tape manufacturing.

The concentration of the solutions can vary between 0.3 M and 1.5 M. The thickness of the sheet obtained does not must exceed values of up to 600 nm, if you want to preserve The quality of the material.

Pyrolysis

Once it has been synthesized and deposited the precursor on the LaAlO 3 substrate, the layer is pyrolyzed in an oven controlling the atmosphere. Ascent ramps can vary over a wide range, starting at 300ºC / h and arriving up to 1,500ºC / h between 50ºC and 250ºC and up to 600ºC / h between 250ºC and a temperature between 300 ° C and 350 ° C. Temperature Maximum is maintained between 10 and 60 minutes. The flow is O_ {2} pure varying between 0.02 l / min and 0.6 l / min in a quartz tube 23 mm in diameter, at a pressure of 1 bar and a pressure of H2O 24 mbar

Heat treatment

The heat treatment is carried out in an oven It controls the temperature as well as the ramps for your changes. The substrate must be kept inside a quartz tube 23 mm in diameter in a controlled atmosphere throughout the process. Normally a mixture of the gases of N2 and O_ {2}, with a range of 0.012 to 0.6 l / min for N_ {2} and between 0.006 to 0.03 l / min for O2. This results in speeds linear between 0.80 mm / s and 24 mm / s. The maximum temperature at which the heat treatment is carried out can vary over a wide range, usually between 750ºC and 820ºC, while the ramps up and down can also be variables The choice of the maximum temperature at which it is made the heat treatment will basically determine two characteristics thin sheet morphological: the grain size of the oxide and its roughness. The total time the sample will remain at maximum temperature will normally be 90 minutes, although it can vary over a wider range. Features are obtained optimized when the procedure described above is it takes place in a temperature range of between 250ºC and a temperature between 300ºC and 350ºC with a ramp included  between 30ºC / h and 600ºC / h and finally remaining at the temperature maximum for a time that can be between 10 minutes and 90 minutes.

This process is followed by another heat treatment at high temperature for crystallization of the sheet superconductor that takes place in an oven in atmosphere controlled and comprising the following two phases. A first heating stage performed in a formed atmosphere mainly by nitrogen (with a water vapor pressure between 7 mbar and 100 mbar and an oxygen pressure between 0.1 mbar and 1 mbar) up to a temperature between 750ºC and 820ºC and staying at this temperature between 30 and 120 minutes and a second heating stage at a temperature between 500ºC and 300ºC in an oxygen bar for less than about 8 hours finally followed by a cooling process until room temperature.

Once described the thermal process to which submit the samples should be recorded what is the structure and morphological characteristics that generate thin sheets epitaxials These determinations were made from X-ray diffraction diagrams of Electron Microscopy Scanning and Microscopy of Atomic Forces. The description of said analyzes to deposits made on a single crystal of LaAlO_ {3}, are described in the examples detailed to then, although it could also be used as a substrate, any metal tape conveniently protected with an oxide layer grown epitaxially.

Description of the figures

Figure 1- Flowchart illustrating the different stages of the precursor synthesis process anhydrous metalorganics from a generic MM'O oxide via of attack with anhydride of that same starting oxide.

Figure 2- Flowchart illustrating the different stages of the process of synthesis of the precursor solution from YBCO.

Figure 3- IR spectrum of the precursor solution of TFA where the characteristic carboxylate band is observed around 1680 cm -1.

Figure 4- Intensity of the carboxylate peak in the IR spectra as a function of heat treatment time at 250 ° C (figure 4b) and 300 ° C (figure 4a).

Figure 5- Optical Microscopy Images of pyrolized sheets in optimal conditions (figure 5a) and unacceptable conditions (with cracks (figure 5b) or with undulations (figure 5c)).

Figure 6- General scheme of treatments thermal used for pyrolysis. The ramps up the temperature, isothermal treatment temperature and time can be modified in the ranges indicated.

Figure 7- Image obtained by TEM of a YBCO thin sheet on a LaAlO 3 substrate, then of the pyrolysis process where particles can be seen nanometric

Figure 8- SEM images after a optimal growth of a thin YBCO sheet over a LaAlO 3 substrate. Figures 8a and 8b correspond to the Same sample at different magnifications. In them you can see that there are few pores and the size of these is very small, giving as result a good critical current.

Figure 9- Graph of the critical current in temperature function for a YBCO sheet grown in optimal conditions.

Figure 10- Type X-ray diagram the-2 the in which the peaks can be seen of Bragg (001) of the YBCO phase and (h00) of the substrate of LaAlO_ {3}.

Examples of embodiment of the invention Example I

A solution of 50 mL of Y, Ba and Cu trifluroacetates with a concentration of 1.5 M (Y: Ba: Cu ratio of 1: 2: 3). For this, 8.334 g (0.0125) were weighed. moles) of commercial YBa_ {Cu} {3} O7 in a spherical flask 250 mL, coupled to a Dimroth refrigerant and equipped with magnetic stirring In addition, 25 mL of dry acetone was added. freshly distilled, 22 mL of trifluoroacetic anhydride (0.000156 moles) (slow addition to avoid overheating) and 5 mL of trifluoroacetic acid. The mixture was heated at 50 ° C for 72 hours in an inert atmosphere (Ar). Then it cooled to room temperature and filtered through a 0.45 filter \ mum. The resulting solution was then evaporated at reduced pressure using a rotary evaporator, first to room temperature (2 hours) and then gradually warming to 80 ° C, obtaining the trifluoroacetates of Y, Ba and Cu (characterized by its IR spectrum (figure 3)). A part of solid obtained was dissolved in acetone and another in methanol keeping both solutions in closed vials and in atmosphere inert.

Both the ketone solution and the Methanolic ICP analyzes (1: 1.98: 2.97) were performed with the in order to verify that the relationship had been maintained initial stoichiometric. An evaluation of the water content of the powder sample and it was seen that it was by below detection limits using technique Karl-Fischer (less than 1 ppm). IR spectrum of the mixture evidenced the existence of the bands a 1650-1720 cm -1 corresponding to the Trifluoroacetates formed.

Example II

From the trifluoroacetates of Y, Ba and Cu, deposition (14 µl) was performed on a LaAlO 3 substrate (dimensions 5 mm * 5 mm, thickness 0.5 mm and orientation (100)) using the Spin-coating technique (6000 rpm for 2.O2 minutes). It is necessary to perform the experiment in a controlled atmosphere room because high humidity in the medium can deteriorate the fat solution. Then you he performed the pyrolysis, consisting of the decomposition of the organic material. For this, an alumina crucible was used (where the substrate is placed) which was introduced into a 23 mm quartz tube in diameter, which was placed inside an oven. The program followed by the oven is the one described in figure 6 with a ramp of 300ºC / h up to a maximum temperature of 309ºC, which was maintained for 30 minutes The use of a controlled atmosphere is needed inside the oven, for this we worked with a pressure of 1 bar oxygen, a flow of 0.05 l / min and a water pressure of 24 mbar This humidity is achieved by passing the gas through some wash bottles equipped with a porous plate in its lower part internal, to divide the gas into small drops, thus increasing the water contact surface. At the end of the process, the Sample was stored in a desiccator.

The sheet obtained was characterized by Optical Microscopy (Figure 5a), where you can see a distribution homogeneous, without cracks or roughness and by microscopy Transmission electronics to confirm that the layer retains its homogeneity on a nanometric scale (figure 7). Were also performed a series of IR spectra obtained from sheets treated during different times and at two different temperatures (figure 4a and 4b). These experiments allowed to confirm the total decomposition of organic matter (the disappearance of the carboxylate group). From this way it is possible to determine what the minimum duration should be of the pyrolysis process of the layer.

In other cases, when the solution concentration of the trifluoroacetates of Y, Ba and Cu, the samples show cracks due to the stresses generated (with increasing concentration, the resulting sheet has a greater thickness and that generates greater tensions resulting in the crack formation (figure 5b)). When the solution precursor was not homogeneous may appear precipitated being able to form sheets that have different thicknesses and roughnesses (figure 5c) that subsequently reduce their quality.

Example III

From a pyrolized layer, the heat treatment to achieve phase formation YBa_ {2} Cu_ {3} O_ {7}. It worked with an oven, which is applied a rapid rise in temperature (25ºC / min) until reaching 795 ° C. This temperature was maintained for 180 minutes (all 30 last minutes dry) and then a ramp was applied to a 2.5ºC / min speed up to room temperature. In this case 0.2 mbar of O2 and 7 mbar of water pressure was used. He gas flow was what allows the mass flow controller used (Bronkhorst High-Tech) to perform the mix with a range of 0.012 to 0.6 l / min for the N2 and between 0.006 and 0.03 l / min for the O2. Without taking the sample out of the oven, oxygenation of said sample was performed using the same dry atmosphere It was raised to 450 ° C, the carrier gas was changed to Dry O 2 at 1 bar pressure and maintained at this temperature for A time of 90 minutes. Then a ramp was made to 300ºC / h to room temperature.

Sample characterization was performed using SEM images (figure 8), current measurements critical at 5K (J_ {c} = 3.3 * 10 7 A / cm2) and at 77 K (J_ {c} = 4.3 * 10 6 A / cm 2) (figure 9) and DRX analysis (figure 10).

Claims (25)

1. Procedure for obtaining material anhydrous metalorganic from its oxides comprising Next steps:

to)

oxide powder solution in:

i)

a anhydride corresponding to an organic acid capable of dissolving said oxide,

ii)

a small amount of organic acid from point i) that acts as reaction catalyst, and

iii)

acetone as solvent,

b)

heating the mixture in atmosphere inert,

C)

filtration of the resulting suspension at room temperature,

d)

evaporation of the resulting mixture with a rotary evaporator under reduced pressure,

and)

solid waste redisolution as well obtained, and

F)

optionally, storage of trifluoroacetates thus obtained in vials in atmosphere inert.

2. Procedure for obtaining material anhydrous metalorganic according to claim 1 wherein step a) is performed using trifluoroacetic anhydride ((CF 3 CO) 2 O), a small amount of acid trifluoroacetic acid (CF 3 COOH) as the reaction catalyst and Acetone as solvent. 3. Method for obtaining anhydrous metalorganic material according to claims 1 and 2, characterized in that the amount of trifluoroacetic acid used as a catalyst in step a) is 5% by volume. 4. Method for obtaining anhydrous metalorganic material according to claims 1 to 3, characterized in that the dissolution of step a) is carried out in a flask coupled to a Dimroth refrigerant and provided with magnetic stirring. 5. Method for obtaining anhydrous metalorganic material according to claims 1 to 4, characterized in that step b) is carried out at a temperature between 45 ° C and 50 ° C in an Ar atmosphere for 50-80 hours. 6. Method for obtaining anhydrous metalorganic material according to claims 1 to 5, characterized in that step d) is carried out at a temperature between 75 ° C and 85 ° C, and at a pressure between 0.6 mbar and 2 mbar. 7. Method for obtaining anhydrous metalorganic material according to claims 1 to 6, characterized in that the redisolution of step e) uses acetone as the solvent. 8. Method for obtaining anhydrous metalorganic material according to claims 1 to 6, characterized in that the redisolution of step e) uses methanol as a solvent. 9. Procedure for obtaining material anhydrous metalorganic consisting of trifluoroacetates from Y, Ba and Cu from YBCO comprising the following steps:

to)

YBCO powder solution in trifluoroacetic anhydride ((CF 3 CO) 2 O), a small amount of trifluoroacetic acid (CF 3 COOH) as reaction catalyst and acetone as solvent,

b)

heating the mixture in atmosphere inert during

C)

filtration of the resulting suspension at room temperature,

d)

evaporation of the resulting mixture with a rotary evaporator under reduced pressure, and

and)

solid waste redisolution as well obtained.

10. Procedure for obtaining material anhydrous metalorganic according to claim 9 to which the storage of trifluoroacetates obtained in vials in inert atmosphere as a last step. 11. Method for obtaining anhydrous metalorganic material according to claims 9 and 10, characterized in that the amount of trifluoroacetic acid used as catalyst in step a) is 5% by volume.

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12. Method for obtaining anhydrous metalorganic material according to claims 9 to 11, characterized in that the dissolution of step a) is carried out in a flask coupled to a Dimroth refrigerant and provided with magnetic stirring. 13. Method for obtaining anhydrous metalorganic material according to claims 9 to 12, characterized in that step b) is carried out at a temperature between 45 ° C and 50 ° C in an atmosphere of Ar for 50-80
hours, 14. Method for obtaining anhydrous metalorganic material according to claims 9 to 13, characterized in that step d) is carried out at a temperature between 75 ° C and 85 ° C, and at a pressure between 0.6 mbar and 2 mbar. 15. Method for obtaining anhydrous metalorganic material according to claims 9 to 14, characterized in that the redisolution of step e) uses acetone as the solvent. 16. Method for obtaining anhydrous metalorganic material according to claims 9 to 15, characterized in that the redisolution of step e) uses methanol as a solvent. 17. Trifluoroacetate obtained according to the procedures of claims 1 to 9 characterized in that its water content is less than 1 pmm. 18. Trifluoroacetate obtained according to the procedures of claims 9 to 16 characterized in that it is a trifluoroacetate of Y and that its water content is less than 1 pmm. 19. Trifluoroacetate obtained according to the procedures of claims 9 to 16 characterized in that it is a Ba trifluoroacetate and that its water content is less than 1 pmm. 20. Trifluoroacetate obtained according to the procedures of claims 9 to 16 characterized in that it is a Cu trifluoroacetate and that its water content is less than 1 pmm. 21. Use of trifluoroacetate claim 17 as anhydrous metalorganic precursor for the deposition and growth of layers and ribbons of oxides. 22. Use of trifluoroacetate claims 18 to 20 as anhydrous metalorganic precursor for the deposition and growth of superconducting layers and tapes. 23. Process for obtaining superconducting material in the form of a layer characterized by the use of anhydrous chemical solutions of the trifluoroacetate type of claims 18 to 20 for the deposition of the superconducting sheet, and because it comprises the following steps:

to)

surface cleaning substrate,

b)

deposition of the chemical solution by any method that allows to obtain a homogeneous thickness and control the thickness of the sheet obtained, in an atmosphere controlled with low humidity,

C)

quick drying of the chemical solution of b), at temperatures below 250 ° C using a rising ramp of temperature between 300ºC / h and 1,500ºC / h in an oxygen flow at a pressure of 1 bar and a pressure of H2O of 24 mbar, and maintaining the maximum temperature between 10 and 60 minutes.

d)

decomposition of precursors metalorganic by heat treatment in atmosphere controlled oxygen, nitrogen or a mixture of both using a controlled gas flow corresponding to a linear speed between 0.80 mm / s and 24 mm / s, at the same time as a temperature rise between 250ºC and a temperature included between 300ºC and 350ºC with a ramp between 30ºC / h and 600ºC / h and finally staying at the maximum temperature for a time that can be found between 10 minutes and 90 minutes, Y

and)

high temperature heat treatment for the crystallization of the superconducting sheet that leads to conducted in an oven in a controlled atmosphere and comprising following phases:

i)

a first stage of heating performed in a formed atmosphere mainly by nitrogen (with a water vapor pressure between 7 mbar and 100 mbar and an oxygen pressure between 0.1 mbar and 1 mbar) up to a temperature between 750ºC and 820ºC and staying at this temperature between 30 and 120 minutes and

ii)

a second heating stage at a temperature between 500 ° C and 300 ° C in an oxygen bar for a time less than about 8 hours finally followed by a cooling process until room temperature.

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24. Method for obtaining superconducting material in the form of a layer of claim 23, characterized in that the deposition of the chemical solution in step b) is carried out by "spin-coating". 25. Method for obtaining superconducting material in the form of a layer of claim 23, characterized in that the deposition of the chemical solution in step b) is carried out by dip-coating.