Chemical pressure effects on the spectroscopic properties of Nd^3+-doped gallium nano-garnets

Abstract

Nd 3+-doped RE 3 Ga 5 O 12 (RE = Gd, Y, and Lu) nano-crystalline garnets of 40-45 nm in size have been synthesized by a sol-gel method. With the decrease of the RE atom size, the chemical pressure related to the decreasing volumes of the GaO 4 tetrahedral, GaO 6 octahedral and REO 8 dodecahedral units drive the nano-garnets toward a more compacted structure, which is evidenced by the change of the vibrational phonon mode frequencies. The chemical pressure also increases the crystal-field strength felt by the RE 3+ ions while decreases the orthorhombic distortion of the REO 8 local environment. These effects alter the absorption and emission properties of the Nd 3+ ion measured in the near-infrared luminescence range from 0.87 to 1.43 μm associated with the 4 F 3/2 → 4 I J (J = 9/2, 11/2, 13/2) transitions. The 4 F 3/2 luminescence decay curves show non-exponential behavior due to dipole-dipole energy transfer interactions among Nd 3+ ions that increases with pressure.

Infrared‐to‐Visible Light Conversion in Er3+–Yb3+:Lu3Ga5O12 Nanogarnets

“…The Lu 3 Ga 5 O 12 garnet crystalline structure can be described as a three dimensional network of GaO 6 octahedra and GaO 4 tetrahedra linked by sharing oxygen ions at the corners of the polyhedron . These polyhedra are arranged in chains along the three crystallographic directions and form dodecahedral cavities that are occupied by the Ln 3+ ions . Due to ionic size considerations in the LuGG lattices, the Er 3+ and Yb 3+ ions are expected to predominantly enter into the distorted dodecahedral sites by replacing Lu 3+ .…”

Light emission and structure of Nd-doped Si-rich-HfO2 films prepared by magnetron sputtering in different atmospheres

“…Note that the majority researchers were focused early on the investigation of the near-infrared PL spectrum in the range 800-1400 nm [10][11][12][13][14][15][16]. Typical radiative emission bands of Nd 3+ ions in the mentioned range can be detected at 880, 1060, and 1350 nm [10,[22][23][24]. These emission bands originate from the electronic transitions between 4f N levels: 4 F 3∕2 → 4 I 9∕2 , 4 F 3∕2 → 4 I 11∕2 and 4 F 3∕2 → 4 I 13∕2 in Nd 3+ ions (Table 4).…”

“…Among different rare-earth ions, the trivalent neodymium (Nd 3+ ) was used in the inorganic laser materials attracting the great attention of scientific researches and industrial applications. Nd 3+ ions exhibit broad and strong absorption band around 800 nm and a very intense emission in the near-infrared luminescence range from 800 to 1430 nm associated with the 4 F 3/2 → 4 I J (J = 9/2, 11/2, 13/2) optical transitions in the 4f inner electronic shell of Nd 3+ ions, following a known "fourlevel" scheme [10,11]. The 4 F 3/2 emitting state can be populated conveniently by the emission of low-cost commercially available laser diodes.…”

“…In addition, it has many intense pumping levels and efficient upconverted emissions [11]. Among different host matrix materials, the garnets [10], glasses [12], ceramics [13], II-VI compounds [14], as well as Si-rich SiO 2 or Si 3 N 4 are the most studied [15,16].…”

Phase transformation and light emission in Er-doped Si-rich HfO2 films prepared by magnetron sputtering

“…8,9 Some papers were related to the emission study in the HfO 2 films doped with the rare-earth elements, such as Nd, Er, Pr, etc. 7,[10][11][12][13][14] Among different rare-earth trivalent elements, the Er 3+ ion is one of the most popular due to its radiative transitions in the green ( 4 S 3/2 → 4 I 15/2 ) and infrared ( 4 I 13/2 → 4 I 15/2 ) spectral ranges being extensively used as an eye-safe source in the atmosphere, laser radar, and medical and surgical applications ( 4 I 11/2 → 4 I 13/2 ). 15,16 However, the number of papers related to the spectroscopic investigation of HfO 2 ;Er based materials is few.…”