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:
10.1002/ente.201300102
Ultrathin Surface Modification by Atomic Layer Deposition on High Voltage Cathode LiNi 0.5 Mn 1.5 O 4 for Lithium Ion Batteries


LiNi0.5Mn1.5O4 particles were synthesized through solid-state reactions. Nickel acetate [Ni(Ac)2[?]4 H2O] and manganese acetate [Mn(Ac)2[?]4 H2O] were mixed at a molar ratio of Ni/Mn=1:3 and milled in a mortar. After heating at 500 degC for 5 h, lithium acetate (LiAc[?]2 H2O) was added to the mixture at a molar ratio of Li/Ni/Mn=2.1:1:3 (5 % excess Li source was added to balance for the volatilized Li during calcination), and the mixture was heated to 500 degC for 5 h once more. Then the mixture was milled and sintered at 950 degC for 10 h followed by annealing at 700 degC for 10 h.
[{"arguments": [["LiNi0.5Mn1.5O4", "Recipe_Target"]], "trigger": "synthesized"}, {"arguments": [["Mn", "Participant_Material"], ["Nickel acetate", "Recipe_Precursor"], ["Ni", "Participant_Material"], ["manganese acetate", "Recipe_Precursor"]], "trigger": "mixed"}, {"arguments": [["Li", "Participant_Material"], ["Mn", "Participant_Material"], ["mixture", "Participant_Material"], ["lithium acetate", "Recipe_Precursor"], ["Ni", "Participant_Material"]], "trigger": "added"}, {"arguments": [["mixture", "Participant_Material"]], "trigger": "heated"}, {"arguments": [["Li", "Participant_Material"]], "trigger": "added"}, {"arguments": [["mixture", "Participant_Material"]], "trigger": "milled"}]