Combining second-order Jahn-Teller distorted cations to create highly efficient SHG materials: synthesis, characterization, and NLO properties of BaTeM2O9 (M = Mo6+ or W6+).
Combining second-order Jahn-Teller distorted cations to create highly efficient SHG materials: synthesis, characterization, and NLO properties of BaTeM2O9 (M = Mo6+ or W6+).
复制标题
DOI：
10.1021/ja035314b
复制
发表时间：
2003-06
影响因子：
15
通讯作者：
Hyun-Seup Ra;K. Ok;P. Halasyamani
中科院分区：
文献类型：
--
作者：
Hyun-Seup Ra;K. Ok;P. Halasyamani
两种新的氧化物，BaTeMo 2 O 9和BaTeW 2 O 9，已合成，通过标准的固态技术，具有强的SHG强度约600 × SiO2，在LiNbO 3的顺序。这两种材料都含有易受二阶Jahn-Teller（SOJT）畸变影响的阳离子，从而导致不对称的配位环境。SOI畸变使M6+-O和Te 4 +-O键极化。同样重要的是，这些偏振相长地相加，导致大的SHG响应。BaTeM_2 O_9（M = Mo ~（6+）或W ~（6+））的粉末倍频测量表明，这两种材料都是相匹配的，其衍射效率分别为28和22 μ m/V。用Te ~（4+）-O和Mo ~（6+）-O的键超极化率分别为130 × 10 ~（-40）和305 × 10 ~（-40）m ~ 4/V，计算出BaTeMo ~（2+）O ~（9+）的键超极化率为20 μ m/V。此外，通过粉末二次谐波测量，我们能够给出一个更合理的β（W 6 +-O）值，230 × 10-40 m4/V。这个值与W 6+的较小的极化率和八面体内畸变的幅度相比，Mo 6+是一致的。
Two new oxides, BaTeMo2O9 and BaTeW2O9, have been synthesized, by standard solid-state techniques, that have strong SHG intensities of approximately 600 x SiO2, on the order of LiNbO3. Both materials contain cations susceptible to second-order Jahn-Teller (SOJT) distortions, resulting in asymmetric coordination environments. The SOJT distortion polarizes the M6+-O and Te4+-O bonds. Equally importantly, these polarizations constructively add, resulting in the large SHG responses. Powder SHG measurements on BaTeM2O9 (M = Mo6+ or W6+) indicated that both materials are phase-matchable and have a deffexp of 28 and 22 pm/V, respectively. Using bond hyperpolarizability values (beta's) of 130 x 10-40 and 305 x 10-40 m4/V for Te4+-O and Mo6+-O respectively, we calculate a deffcalc of 20pm/V for BaTeMo2O9. In addition, through the powder SHG measurements, we are able to give a more reasonable value for beta(W6+-O), 230 x 10-40 m4/V. This value is consistent with the smaller polarizability and magnitude of the intra-octahedral distortion of W6+ compared with Mo6+.