Nanocrystalline Compound Research Articles

Effect of Autoclaving on the Physicochemical Properties and Biological Activity of Aluminum Oxyhydroxide Used as an Adjuvant in Vaccines.

The long-term biodistribution of non-biodegradable microstructures or nanostructures used in vaccinations is widely unknown. This is the case for aluminum oxyhydroxide, the most widely used vaccine adjuvant, which is a nanocrystalline compound that spontaneously forms nanoprecipitates. Although generally well-tolerated, aluminum oxyhydroxide is detected in macrophages a long time after vaccination in individuals predisposed to the development of systemic and neurological aspects of the autoimmune (inflammatory) syndrome induced by modified adjuvant. In the present study, we established that the terminal sterilization of aluminum oxyhydroxide by autoclaving in final container vials produced measurable changes in its physicochemical properties. Moreover, we found that these changes included (1) a decreasing in the pH of aluminum oxyhydroxide solutions, (2) a reduction in the adsorption capacity of bovine serum albumin, (3) a shift in the angle of X-ray diffraction, (4) a reduction in the lattice spacing, causing the crystallization and biopersistence of modified aluminum oxyhydroxide in the macrophage, as well as in muscle and the brain.

Observation of Griffith like phase and large magnetocaloric effect in nanocrystalline La0.7Ag0.2Bi0.1MnO3

In this paper, we present structural, magnetic, magnetocaloric, and critical study of perovskite La0.7Ag0.2Bi0.1MnO3 (LABMO) nanocrystalline compound synthesized by the sol–gel method. Temperature dependent magnetization measurements reveal the significant suppression of ferromagnetism in the LABMO sample upon Bi-doping on a La-site. The downturn in inverse magnetic susceptibility (χ−1) observed just above TC (236 K) in the paramagnetic regime corroborates the presence of short-range ferromagnetic correlations, which is the characteristic of the Griffith like phase below 270 K. The deviation from linear paramagnetic behavior in χ−1 implies the strong Griffith singularity. Furthermore, we have employed an integrated Maxwell's thermodynamic relation numerically and used isothermal magnetization data to determine the change in magnetic entropy at various magnetic fields. For a magnetic field change of 5 T, the value of maximum magnetic entropy change is found to be ∼6 J kg−1 K−1. We have also explored the critical behavior of the LABMO sample at transition temperatures using different theoretical models. The value of exponents β, γ, and δ does not fall into any known universality class. Despite this, the scaling relations show that interactions are renormalized around the Curie temperature (TC). The exponent n ≤ 2 extracted from field dependency on the magnetic entropy change confirms the second-order phase transition in LABMO.

Magnetic and magnetocaloric properties of nanocrystalline sample of a glassy ferromagnetic compound: Modification of short range ordering

The modification of magnetic interactions due to the reduction of particle size has been explored in the case of nanocrystalline Gd0.5Sr0.5MnO3 compound. In contrast to the normal ferromagnetic or antiferromagnetic compounds, the studied nanoparticle exhibits quite different magnetic and magnetocaloric properties. The experimental outcomes are also compared with its bulk counterparts having disordered ferromagnetic ground state. Additionally, at the cryogenic temperature range, the significant magnetocaloric effect in both the samples indicate the applicability as a suitable magnetic refrigerant material. Moreover, the desertion nature of the magnetic hysteresis loop due to the field cycling indicates the superiority of the nanocrystalline compound over its bulk counterpart.

Study of devitrification of kinetically arrested magnetic phase and magnetocaloric effect for nanocrystalline Pr0.65(Ca0.7Sr0.3)[formula omitted]MnO[formula omitted] compound

Magnetic and magnetocaloric effect of nanocrystalline Pr0.65(Ca0.7Sr0.3)0.35MnO3 compound have been investigated. In addition to the charge ordering and antiferromagnetic ground state, several fascinating physical properties were appear depending upon the controllable phase separation scenario. The different proportions of the magnetic phases appeared at the low temperature is directly related with the history of applied magnetic field and temperature. Moreover, the nucleation (arrested magnetic phase) and devitrification nature of magnetic phase were addressed considering different widths of the supercooling and kinetic arrest bands. Additionally, nanocrystalline compound exhibits the large inverse magnetocaloric effect at low temperature. The inverse magnetocaloric effect arises possibly due to the arrested antiferromagnetic phase of this compound.

Magnetic and magnetocaloric properties of the nanocrystalline Pr0.7Ba0.2Ca0.1MnO3 sample

We have investigated the structural and magnetization properties of the nanocrystalline Pr0.7Ba0.2Ca0.1MnO3 sample, synthesized using the sol–gel method. The Rietveld refinement of the X-ray diffraction pattern of the nanocrystalline sample (recorded at room temperature) confirmed the formation of the orthorhombic crystal structure with Pnma space group. The temperature dependent magnetization M(T) measurements suggested that the present sample undergoes a paramagnetic to ferromagnetic phase transition and the Curie temperature was found to be ∼ 126 K. The positive slopes observed from the Arrott plots for the present sample indicate the second order of magnetic phase transition, as per the Banerjee’s criterion. The maximum value of magnetic entropy change |ΔSMmax| and relative cooling power (RCP) were found to be ∼ 2.2 J kg-1K-1 and 261 Jkg-1 for a magnetic field change of 5 T. The phenomenological universal curve was constructed for the present sample and ΔSM curves were found to collapse into one, and the universal curve confirmed the second order of magnetic phase transition. The relatively large values of |ΔSM| and RCP make the present nanocrystalline compound promising for the magnetic refrigeration technology.

Study of magnetic and magneto-transport properties of nanocrystalline [formula omitted][formula omitted][formula omitted] compound: Observation of large magnetoresistance

Magnetic and magneto-transport properties of nanocrystalline Nd0.5Ca0.5MnO3 compound are presented. In contrast to its bulk counterparts, with modification of the magnetic grounds state, large magnetoresistance appeared in the presence of comparatively lower magnetic field in nanocrystalline compound. Additionally, the magnetic field induced insulator-metal transition took place in nanocrystalline compound with negligible thermal hysteresis. From application perspectives, observation of the low field magnetoresistance in this compound may be important for several uses in magnetic field sensor related technology. Fundamentally, the influences of the ferromagnetic phase fraction as well as the induced ferromagnetic interaction in nanocrystalline samples on magnetic and magneto-transport properties were addressed.

Comparison of structural, magnetic and electrical transport behavior in bulk and nanocrystalline Nd-lacunar Nd0.67Sr0.33MnO3 manganites

Abstract Bulk and nanocrystalline Nd-lacunar Nd0.67Sr0.33MnO3 manganites were synthesized, and the structural, magnetic and electrical properties have been systematically studied. The Rietveld refinement confirms perovskite structure with orthorhombic crystal symmetry (Pbnm space group). The bulk compound shows a sharp second order transition at 275 K while the nanocrystalline compound exhibit a broadened transition with a TC of 242 K. Temperature dependence of electrical resistivity of both the compounds witness double peaks; a sharp peak near TC and a broad peak below TC, which is more prominent in the nanocrystalline compound whereas former peak is more prominent in the bulk compound. The combined effect of Kondo-like spin-dependent scattering and electron-electron interactions dominates the transport properties at low temperature in the nanocrystalline compound and results in upturn enhancement in resistivity, while the high-temperature insulating behavior of both compounds can be explained by the adiabatic small polaron hopping mechanism. The effective Mn ion valence of bulk and nanocrystalline compounds are found to be 3.56 and 3.25 and the observed crystal field splitting energy is slightly higher for the nanocrystalline compound. X-ray absorption spectra result quantitatively demonstrates that the broken symmetry at the surface of nanocrystalline compound aid to stabilize more Mn3+ ions that lead to interesting magnetic and electrical transport behavior.

Eu valence transition behavior in the nano form of EuPd2Si2

The compound EuPd2Si2 is a well-known fluctuating-valent compound with a largest variation of Eu valence in a narrow temperature interval (around 150 K). The ball-milled form of this compound was investigated to understand the Eu valence behavior in the nanoform. The compound is found to retain the ThCr2Si2-type tetragonal structure after ball-milling leading to a reduction in particle size, typically falling in the range 10–100 nm. We find that there is a qualitative change in the temperature dependence of magnetic susceptibility for such small particles, with respect to that known for bulk form. To understand this microscopically, Mössbauer spectrum as a function of temperature were taken. The Mössbauer spectra of the nanocrystalline compound is essentially divalent-like at room temperature, but becomes distinctly bimodal at all temperatures below 300 K, unlike that of the bulk form. That is, there is a progressive transfer of intensity from divalent position to trivalent position with a gradual decrease of temperature. We attribute it to a first-order valence transition, with extreme broadening by defects in the nano specimen. Thus there is a qualitative change in the valence behavior in this compound as the particle size is reduced by ball-milling. Such a particle size study is reported for the first time for a Eu-based mixed valent compound.

Photovoltaic Performance of Co-doped CuCrO2 for p-type Dye-sensitized Solar Cells Application

For the first time, Co-doped CuCrO2+δ non-stoichiometric nanocrystals with δ≈0.1 aresynthesized bylow-temperature hydrothermal method. The synthesis mechanism proposed and the structural characterizations have confirmed that the excess oxygen from delafossite structure is given by the specific hydrothermal conditions (temperature, pressure and molarity of basic solution). The decreasing of the observed electrical resistivity in the non-stoichiometric nanocrystals is enhanced by Co-subtitution. Thus, hydrothermal synthesis has allowed to obtain doped delafossite nanocrystalline compound with excess oxygen and mixed valancies of both sites (A and B sites) and could open the study of its cumulative effect on physical properties. The performance of p-type DSSCs based on Co-doped CuCrO2+δnanocrystals photocathodeswas made using two type of dye: Coumarin C343 and Ruthenium N719. The short-circuit density (Jsc) is notably increased by approximately 60% when N719 is used as dye.

Coercivity enhancement mechanism in Dy-substituted Nd–Fe–B nanoparticles synthesized by sol–gel base method followed by a reduction-diffusion process

In current work, Nd15−xDyxFe77.5B7.5 (at%) nanoparticles with different Dy-content (x=0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0) were synthesized by sol–gel method followed by a reduction-diffusion process. The effects of Dy on the magnetic properties and the relations between the microstructure and the coercivity of Dy-substituted Nd–Fe–B nanoparticles have been studied. The coercivity of Nd–Fe–B nanoparticles with the addition of Dy first increase, reaches a maximum, and then starts to decrease. The coercivity of Dy-substituted Nd–Fe–B nanoparticle synthesized by sol–gel method increased from 938.9 to 1663.9kA/m while the remanence decreased slightly from 1.16 to 1.06T. The results show that with an increase in Dy content the variation of maximum energy product ((BH)max), lowest-order uniaxial magnetocrystalline anisotropy constant (Ku1), and Curie temperature (Tc) had a trend as same as the coercivity. The Henkel plot showed that the existence of exchange coupling interaction between grains, and the exchange coupling interactions increased with increasing x from 0.0 to 2.0 and then decrease with further increasing x≥2.5. The optimum magnetic properties of Nd–Fe–B nanoparticles with (BH)max =40.38 MGOe, Hc=1663.9kA/m, Br=1.08T were obtained by substituted 2.0at% Dy. The effects of increasing temperature on magnetic properties of Dy-substituted Nd–Fe–B nanoparticle magnets with 2.0at% Dy was investigated. The reduced spin-reorientation temperature was obtained for Dy-substituted Nd–Fe–B nanoparticles with 2.0at% Dy. Below 100K a spin-reorientation transition was takes place. The temperature coefficient of coercivity (β) was −0.36, −0.46, −0.41, −0.34, −0.29, −0.24, −0.25%/°C at different temperature 50, 100, 150, 200, 250, 300, 350°C, respectively. Mössbauer spectroscopy was applied to study the composition and properties of Dy-substituted Nd–Fe–B magnet. Microstructure analysis showed a homogeneous distribution of Dy in produced samples. The possible reason for observed magnetic behavior is improving the intrinsic material parameter and optimizing the microstructure by a uniform enhancement of magnetocrystalline anisotropy by formation the nanocrystalline compound (Nd,Dy)2Fe14B.

Temperature dependence of the radiation tolerance of nanocrystalline pyrochlores A2Ti2O7 (A = Gd, Ho and Lu)

A potentially enhanced radiation resistance of nanocrystalline materials, as a consequence of the high density of interfaces and surfaces, has attracted much attention both to understand the fundamental role of these defect sinks and to develop them for high-radiation environments. Here, irradiation response of nanocrystalline A2Ti2O7 (A = Gd, Ho and Lu) pyrochlore powders with grain sizes of 20–30 nm was investigated by 1-MeV Kr2+ ion bombardment. In situ transmission electron microscopy (TEM) revealed that the critical amorphization fluence for each nanocrystalline compound at room temperature was greater than that for their coarse-grained counterparts, indicating an enhanced amorphization resistance. The effect of temperature on the irradiation response of one of these compounds, nanocrystalline Lu2Ti2O7, was further examined by performing ion irradiation at an elevated temperature range of 480–600 K. The critical amorphization temperature (Tc) was found to be noticeably higher in nanocrystalline Lu2Ti2O7 (610 K) than its coarse-grained counterpart (480 K), revealing that nanocrystalline Lu2Ti2O7 is less resistant to amorphization compared to its coarse-grained phase under high temperatures. We interpret these results with the aid of atomistic simulations. Molecular statics calculations find that cation antisite defects are less energetically costly to form near surfaces than in the bulk, suggesting that the nanocrystalline form of these materials is generally less susceptible to amorphization than coarse-grained counterparts at low temperatures where defect kinetics are negligible. In contrast, at high temperatures, the annealing efficiency of antisite defects by cation interstitials is significantly reduced due to the sink properties of the surfaces in the nanocrystalline pyrochlore, which contributes to the observed higher amorphization temperature in the nano-grained phase than in coarse-grained counterpart. Together, these results provide new insight into the behavior of nanocrystalline materials under irradiation.

Crystal structure of magnesium dichloride decahydrate determined by X-ray and neutron diffraction under high pressure.

Magnesium dichloride decahydrate (MgCl2·10H2O) and its deuterated counterpart (MgCl2·10D2O) are identified for the first time by in-situ powder synchrotron X-ray and spallation neutron diffraction. These substances are crystallized from a previously unidentified nanocrystalline compound, which originates from an amorphous state at low temperature. A combination of a recently developed autoindexing procedure and the charge-flipping method reveals that the crystal structure of MgCl2·10H2O consists of an ABCABC··· sequence of Mg(H2O)6 octahedra. The Cl(-) anions and remaining water molecules unconnected to the Mg(2+) cations bind the octahedra, similar to other water-rich magnesium dichloride hydrates. The D positions in MgCl2·10D2O, determined by the difference Fourier methods using the neutron powder diffraction patterns at 2.5 GPa, show the features such as bifurcated hydrogen bonds and tetrahedrally coordinated O atoms, which were not found in other forms of magnesium chloride hydrates.

Size effect on magnetic phase coexistence in Pr0.5Sr0.5Mn1−xCrxO3

Magnetic and transport properties are investigated in Pr0.5Sr0.5Mn1−xCrxO3 (0 x 0.05) focusing on the effect of Cr substitution and particle size dependence. The studies demonstrate that magnetic and transport properties are significantly different for nanocrystalline compound from the bulk. Neutron depolarization and diffraction studies confirm that different fractions of magnetic phase separation between antiferromagnetic and ferromagnetic components, and ferromagnetic domain size give rise to the different magnetic and transport properties. Intriguingly, nanocrystalline compound with x = 0.05 shows apparent signature of arrested state in magnetization and magnetoresistance both in thermal and magnetic field variations which is absent in the bulk counterpart. A spin-glass like state is identified for nano at low temperature, which is argued to be correlated with the arrested or pinning mechanism.

Bio-persistance et distribution systémique des particules injectées par voie intra-musculaire : quelle incidence sur la tolérance à long terme des adjuvants aluminiques ?

Aluminium oxyhydroxide (alum), a nanocrystalline compound that forms agglomerates, has been widely used as a vaccine adjuvant since 1927, but the mechanisms by which it stimulates immune responses remain poorly understood. Although generally well tolerated, alum may occasionally cause chronic health problems in presumably susceptible individuals. Some individuals may rarely develop delayed-onset diffuse myalgia, chronic exhaustion and cognitive dysfunction, associated with long-term persistence (up to 12 years) of alum-loaded macrophages at site of i.m. immunization, defining so-called macrophagic myofasciitis (MMF). Symptoms are consistent with the chronic fatigue/myalgic encephalomyelitis (CFS/ME) syndrome, and have been used as a paradigm of the "autoimmune/inflammatory syndrome induced by adjuvants" (ASIA). Cognitive dysfunction is reminiscent of that described in workers exposed to inhaled Al particles. Individual susceptibility may influence both alum biopersistence and difusion away from injection sites. Biopersistent particles such as fluorescent alum-coated nanohybrids, when injected into mouse muscle, are captured by monocyte-lineage cells and then carried to distant organs, draining lymph nodes and blood, probably via the thoracic duct, with delayed and accumulative translocation to the brain (microglial cells). Brain penetration occurs at extremely low levels in normal conditions, possibly explaining the good tolerance of alum despite its high neurotoxic potential. However, systemic diffusion is considerably enhanced by the potentiating effect of MCP-1, the main monocyte chemoattractant factor, the production of which is subject to marked variations linked to age and to genetic and environmental factors. Selective MCP-1 elevation is the only known circulating biomarker of MMF.

Features of the synthesis and the study of nanocrystalline cobalt-nickel spinel

A nanocrystalline compound nickel cobaltite (NiCo2O4) with the average size of crystals of ∼20 nm at 700°C has been synthesized using the method of combined crystallization of solutions of nitrates with the subsequent thermal and ultrasonic treatment. The optimal sintering mode of the NiCo2O4 powder (1300°C, 2 h, air) has been selected, and ceramics (60–65 nm) with open porosity of 25–30% have been prepared. The temperature and frequency dependences of the electrical conductivity of nickel cobaltite have been studied. It has been assumed that the high values of the electrical conduction and pseudo-capacity of NiCo2O4 are due to the variable valence of Ni and Co in oxides. It is recommended to use cobaltite nickel as an electrode material of a supercapacitor and a catalyst of the oxygen isolation in fuel elements.

Slow CCL2-dependent translocation of biopersistent particles from muscle to brain

BackgroundLong-term biodistribution of nanomaterials used in medicine is largely unknown. This is the case for alum, the most widely used vaccine adjuvant, which is a nanocrystalline compound spontaneously forming micron/submicron-sized agglomerates. Although generally well tolerated, alum is occasionally detected within monocyte-lineage cells long after immunization in presumably susceptible individuals with systemic/neurologic manifestations or autoimmune (inflammatory) syndrome induced by adjuvants (ASIA).MethodsOn the grounds of preliminary investigations in 252 patients with alum-associated ASIA showing both a selective increase of circulating CCL2, the major monocyte chemoattractant, and a variation in the CCL2 gene, we designed mouse experiments to assess biodistribution of vaccine-derived aluminum and of alum-particle fluorescent surrogates injected in muscle. Aluminum was detected in tissues by Morin stain and particle induced X-ray emission) (PIXE) Both 500 nm fluorescent latex beads and vaccine alum agglomerates-sized nanohybrids (Al-Rho) were used.ResultsIntramuscular injection of alum-containing vaccine was associated with the appearance of aluminum deposits in distant organs, such as spleen and brain where they were still detected one year after injection. Both fluorescent materials injected into muscle translocated to draining lymph nodes (DLNs) and thereafter were detected associated with phagocytes in blood and spleen. Particles linearly accumulated in the brain up to the six-month endpoint; they were first found in perivascular CD11b+ cells and then in microglia and other neural cells. DLN ablation dramatically reduced the biodistribution. Cerebral translocation was not observed after direct intravenous injection, but significantly increased in mice with chronically altered blood-brain-barrier. Loss/gain-of-function experiments consistently implicated CCL2 in systemic diffusion of Al-Rho particles captured by monocyte-lineage cells and in their subsequent neurodelivery. Stereotactic particle injection pointed out brain retention as a factor of progressive particle accumulation.ConclusionNanomaterials can be transported by monocyte-lineage cells to DLNs, blood and spleen, and, similarly to HIV, may use CCL2-dependent mechanisms to penetrate the brain. This occurs at a very low rate in normal conditions explaining good overall tolerance of alum despite its strong neurotoxic potential. However, continuously escalating doses of this poorly biodegradable adjuvant in the population may become insidiously unsafe, especially in the case of overimmunization or immature/altered blood brain barrier or high constitutive CCL-2 production.

Hexagonal Nano-Crystalline BCN Films Grown on Si (100) Substrate Studied by X-Ray Absorption Spectroscopy

Hexagonal nano-crystalline boron carbonitride (h-BCN) films grown on Si (100) substrate have been precisely investigated. The films were synthesized by radio frequency plasma enhanced chemical vapor deposition using tris-dimethylamino borane as a single-source molecular precursor. The deposition was performed by setting RF power at 400 - 800 W. The reaction pressure was at 2.6 Pa and the substrate temperature was recorded at 700°C - 800°C. Formation of the nano-crystalline h-BCN compound has been confirmed by X-ray diffraction analysis. The diffraction peaks at 26.3° together with a small unknown peak at 29.2° were elucidated due to the formation of an h-BCN structure. The films composed of B, C, and N atoms with different B-N, B-C, C-N chemical bonds in forming the sp2-BCN atomic configuration studied by X-ray photoelectron spectroscopy. Orientation and local structures of the h-BCN hybrid were studied by near-edge X-ray absorption fine structure (NEXAFS) measurements. The dominant presence of p* and s* resonance peaks of the sp2-hybrid orbitals in the B K-edge NEXAFS spectra revealed the formation of the sp2-BCN configuration around B atoms like-BN3 in h-BN. The orientation was suggested on the basis of the polarization dependence of B K-edge and N K-edge of the NEXAFS spectra.

Intermetallic compound formation in Pd/Al multilayer thin films

Nanolayered palladium/aluminium thin films, with an equiatomic average chemical composition and modulation periods of 5, 14 and 30 nm, were deposited by magnetron sputtering onto stainless steel substrates. The as-deposited Pd/Al multilayer films are composed of Pd- and Al-rich nanolayers, along with the formation of the metastable nanocrystalline compound AlPd at the interfaces, which is particularly evident for short periods. The structural evolution of the multilayer thin films towards the high temperature AlPd phase (HT-AlPd) was studied in-situ using hot X-ray diffraction. Heat treatment leads to a disruption of the nanolayered structure by interdiffusion followed by chemical reaction, leading to the formation of intermetallic compounds. Whatever the period, the films always evolve to the HT-AlPd equilibrium intermetallic compound with a similar phase sequence. In fact, for the Pd–Al system the formation of intermediate intermetallic compounds such as Al3Pd2 could not be avoided, not even by reducing the modulation period. The occurrence of reaction during deposition and the formation of intermediate phases limits the use of Pd/Al, one of the most promising energetic aluminium based multilayer systems, for joining purposes.

Macrophagic myofasciitis: characterization and pathophysiology

Aluminium oxyhydroxide (alum), a nanocrystalline compound forming agglomerates, has been used in vaccines for its immunological adjuvant effect since 1927. Alum is the most commonly used adjuvant in human and veterinary vaccines, but the mechanisms by which it stimulates immune responses remain incompletely understood. Although generally well tolerated, alum may occasionally cause disabling health problems in presumably susceptible individuals. A small proportion of vaccinated people present with delayed onset of diffuse myalgia, chronic fatigue and cognitive dysfunction, and exhibit very long-term persistence of alum-loaded macrophages at the site of previous intramuscular (i.m.) immunization, forming a granulomatous lesion called macrophagic myofasciitis (MMF). Clinical symptoms associated with MMF are paradigmatic of the recently delineated 'autoimmune/inflammatory syndrome induced by adjuvants' (ASIA). The stereotyped cognitive dysfunction is reminiscent of cognitive deficits described in foundry workers exposed to inhaled Al particles. Alum safety concerns will largely depend on whether the compound remains localized at the site of injection or diffuses and accumulates in distant organs. Animal experiments indicate that biopersistent nanomaterials taken up by monocyte-lineage cells in tissues, such as fluorescent alum surrogates, can first translocate to draining lymph nodes, and thereafter circulate in blood within phagocytes and reach the spleen, and, eventually, slowly accumulate in the brain.

Solvothermal synthesis, deposition and characterization of cadmium selenide (CdSe) thin films by thermal evaporation technique

Nanocrystalline compound semiconductor Cadmium Selenide was synthesized by the solvothermal method using Cd(NO 3) 2.4H 2O and Se metal granules. The synthesized nanocrystalline CdSe particles were subjected to vacuum annealing at 450 °C to maintain the hexagonal phase. The as synthesized and annealed powders were analyzed using XRD, SEM, EDX and DTA. The X-ray diffraction pattern of the as synthesized powder shows cubic phase, whereas the 450 °C annealed CdSe powder exhibits hexagonal phase. The annealed nanocrystalline CdSe was pelletized using hydraulic pressure of 5 ton and used to deposit thin films at different substrate temperature like Room Temperature (RT), 150, 250, 350 and 450 °C by thermal evaporation using glass as substrate. The deposited films were subjected to XRD, SEM, EDX, UV–vis, Photoluminescence, Raman Spectroscopy and Hall Effect measurement to study their properties. The thickness of the films was measured with thickness profilometer. The thermally deposited CdSe films exhibit the hexagonal structure with n-type conductivity.