The design and operation of solid-state Raman lasers

Static and dynamic structure of ZnWO4 nanoparticles

“…4). Thus the behavior of the RDFs confirms strong distortion of the WO 6 and ZnO 6 octahedra in nanoparticles and is also favorable to the formation of the short W=O bonds, observed in the Raman spectrum [21].…”

“…The independent analysis of the EXAFS signals at the W L 3 and Zn K edges by model independent approach [24] allowed us to reconstruct the first coordination shell RDFs and to follow their temperature dependencies. The significant distortions of the WO 6 and ZnO 6 octahedra, directly observed in nanoparticles by EXAFS, show only minor temperature dependence. The distortion results in the shortening of metal-oxygen bonds to the nearest oxygen atoms, whereas the longest bonds becomes weaker.…”

“…Crystalline ZnWO 4 has monoclinic (P2/c) wolframite-type structure built up of distorted WO 6 and ZnO 6 octahedra joined by edges into infinite zigzag chains, consisting of octahedral units of the same type and running parallel to c-axis [13,25,26]. The octahedra distortion results in the splitting of the W-O and Zn-O distances into three groups with the bond lengths of 1.790, 1.905, and 2.130 Å for tungsten atoms and 2.023, 2.086, and 2.217 Å for zinc atoms [13,25,26].…”

“…Note very good agreement between the experimental and theoretical firstshell EXAFS signals in Figs. 4, and significant difference between distortions of the WO 6 and ZnO 6 octahedra in nanoparticles and microcrystalline ZnWO 4 (Fig. 5).…”

“…Tungstates having general formula A 2+ WO 4 are extremely interesting compounds, which find many practical applications as scintillators [1,2,3], optical fibres [4], solid state Raman lasers [5,6], catalysts [7], high-temperature solid lubricants [8], gas sensors [9], and phase-change optical memories [10]. Among them wolframite-type ZnWO 4 , also known as mineral sanmartinite, has attracted recently a considerable interest both from experimental and theoretical points of view [11,12,13,14] due to optical and catalytic properties as well as possibility of preparation in nanosized [9,15] and thin film forms [10,16,17].…”