Eutectic crystal and preparation method and application thereof

The invention discloses a eutectic crystal. The eutectic crystal is a continuous crystal formed by uniformly distributing two kinds of crystals, namely BaInZnSm and ZnS crystals at intervals,and has a chemical formula shown as formula I that is BaInZnS-nZnS, wherein in the formula I, x is greater than or equal to 9 and less than or equal to 11, y is greater than or equal to 6and less than or equal to 7, l is greater than or equal to 6 and less than or equal to 7, m is greater than or equal to 25 and less than or equal to 26, and x: y: l: m is equal to 10: 6: 7: 26, and nis greater than or equal to 0 and less than or equal to 30. The eutectic system material has the advantages of phase matching, band gap greater than 3.0 electron volts (3.05 eV), large damage threshold and high frequency multiplication conversion efficiency (2.1*AgGaS2), and has great potential value in the field of infrared nonlinearity. 本申请公开了一种共晶体，所述共晶体是由BaInZnS和ZnS晶体两种晶体均匀间隔分布所形成的一种连晶，具有式I所示的化学式：BaInZnS-nZnS式I其中，9≤x≤11，6≤y≤7，6≤l≤7，25≤m≤26并