You will be shown an abstract from a materials science research paper. Your task is to extract all synthesis operations described in the abstract into a structured JSON format. Your output should be a JSON array. Each entry in the array should be a JSON object describing a single synthesis operation. This object should have the following fields:

- "trigger": A verbal predicate indicating a synthesis operation. This should be a string extracted directly from the abstract.
- "arguments": An array of arguments specifying aspects of the synthesis operation. Each entry in the array should be a length-2 array formatted as [<argument_text>, <argument_type>]. The `argument_text` should be a string extracted directly from the abstract. The `argument_type` should be one of the following types: ["Recipe_Precursor", "Atmospheric_Material", "Participant_Material", "Recipe_Target", "Solvent_Material"].

For instance, suppose an excerpt from the abstract reads:

Tetraethoxysilane (TEOS, 98%) and cetyltrimethylammonium bromide (CTAB, 98%) were purchased from Fluka. The MTTZ-siloxy derivative (triethoxysilyl-propyl-5-mercapto-1-methyl-tetrazole) was synthesized as previously described [38].

This excerpt includes two operations, which could be annotated as follows.

[{"arguments": [["Tetraethoxysilane", "Recipe_Precursor"], ["cetyltrimethylammonium bromide", "Recipe_Precursor"]], "trigger": "purchased"}, {"arguments": [["MTTZ-siloxy derivative", "Recipe_Target"]], "trigger": "synthesized"}]

In your response, please include the JSON and no other text.

Abstract:
10.1039/c5ta08878j
A robust symmetrical electrode with layered perovskite structure for direct hydrocarbon solid oxide fuel cells: PrBa 0.8 Ca 0.2 Mn 2 O 5+δ
In order to fabricate a La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) electrolyte supported cell, the LSGM powder was prepared by the solid state reaction method and a dense electrolyte substrate was prepared by dry pressing followed by sintering at 1475 degC. Stoichiometric amounts of La2O3 (Sigma 99.99%), SrCO3 (Sigma, 99.99%), Ga2O3 (Sigma, 99.99%), and MgO (Sigma, 99.9%) powders were ball milled in ethanol for 24 h. After drying, the mixture was calcined for 6 h. The thickness of the LSGM electrolyte was adjusted to about 250 μm by polishing. LDC (La0.4Ce0.6O2-δ) was also prepared by ball milling stoichiometric amounts of La2O3 and CeO2 (Sigma, 99.99%) in ethanol and then calcined for 6 h. For the preparation of the electrode slurry, disordered Pr0.5Ba0.4Ca0.1MnO3 was mixed with an organic binder, V-006. The Pr0.5Ba0.4Ca0.1MnO3 slurry was applied on both sides of the LSGM pellet by the screen printing method, and then fired at 950 degC in air for 4 h.
[{"arguments": [["La0.9Sr0.1Ga0.8Mg0.2O3-\u03b4", "Recipe_Target"]], "trigger": "fabricate"}, {"arguments": [["LSGM", "Recipe_Target"]], "trigger": "prepared"}, {"arguments": [["substrate", "Participant_Material"]], "trigger": "prepared"}, {"arguments": [["MgO", "Recipe_Precursor"], ["SrCO3", "Recipe_Precursor"], ["Ga2O3", "Recipe_Precursor"], ["La2O3", "Recipe_Precursor"], ["ethanol", "Solvent_Material"]], "trigger": "ball milled"}, {"arguments": [["mixture", "Participant_Material"]], "trigger": "drying"}, {"arguments": [["LSGM", "Recipe_Target"]], "trigger": "adjusted"}, {"arguments": [["LDC", "Recipe_Target"]], "trigger": "prepared"}, {"arguments": [["ethanol", "Solvent_Material"]], "trigger": "ball milling"}, {"arguments": [["Pr0.5Ba0.4Ca0.1MnO3", "Participant_Material"], ["LSGM", "Recipe_Target"]], "trigger": "applied"}, {"arguments": [["air", "Atmospheric_Material"]], "trigger": "fired"}]