New potential materials for infrared nonlinear optics. Preparation, characterisation and optical transparency of monometallic and bimetallic iodates

Structures and properties of functional metal iodates

“…For example, NaI 3 O 8 , containing zero-dimensional I 3 O 8  polyanionic units displays a SHG response that is comparable to that of -LiIO 3 [19], and Cs 2 I 4 O 11 with a HTO-like (hexagonal tungsten oxide) 2D layer of I 4 O 1 2 1  anions shows a SHG efficiency of 300 × -SiO 2 (Figure 1) [20]. So far, a number of ternary metal iodates have been reported, the cations used include alkali, alkaline earth, transition metal, lanthanide, and post-transition metal main group elements [19,20,[24][25][26][27][28][29][30][31][32][33]. A family of actinide iodates (mostly U(VI) and Th(IV)) have also been reported by the AlbrechtSchmitt group [34][35][36][37][38][39][40][41][42][43][44].…”

Promising Material for Infrared Nonlinear Optics: NaI3O8 Salt Containing an Octaoxotriiodate(V) Anion Formed from Condensation of [IO3]− Ions

“…[6,7,11,14,20] Recently, we have shown that metallic iodates are particularly interesting for infrared applications as they possess a large domain of transparency from the visible region to the beginning of the far-IR region (12.5 mm), thus covering the three atmospheric transparency windows. [6][7][8] Furthermore, they present high nonlinear coefficients and high optical damage thresholds on powders. Their preparation is simple and reproducible; they are thermally stable at least up to 400 8C.…”

“…In contrast to a-LiIO 3 , which shows an absorption band at 6.5 mm and two others around 3 mm and 6 mm attributable to H 2 O, NaI 3 O 8 is not hygroscopic and is transparent in both atmospheric transparency windows as all metallic iodates previously studied. [6][7][8] …”

Recent advances on second-order NLO materials based on metal iodates

“…A series of divalent metal iodates, namely, M(IO 3 ) 2 (M = Mg, Mn, Co, Ni, Zn), were reported by Gautier-Luneau et al [63]. These isostructural compounds crystallized in polar space group P2 1 , and their structure features a 3D network composed of MO 6 octahedra bridged by tridentate iodate groups (Fig.…”

“…Later, a number of NLO materials based on ternary metal iodates such as anhydrous divalent M(IO 3 ) 2 (M = Mg, Zn, Hg) [63,65], and trivalent metal iodates such as La(IO 3 ) 3 [68] and ␣-In(IO 3 ) 3 [66] were obtained, but they have twinning or phase transition problems, hence a lot of research efforts have been devoted to the explorations for new metal iodates with enhanced SHG performance and higher thermal stability. A number of metal iodates containing polyiodate anions (I O I bridges) possess very large SHG effects [73][74][75][76].…”