Compara mètodes

	Àrea superficial BET	Anàlisi Termogravimètrica	Refinament Rietveld de DRX
Camp	Ciència de materials	Ciència de materials	Ciència de materials
Família	Process / pipeline	Process / pipeline	Process / pipeline
Any d'origen	1938	1960s	1969
Autor original	Brunauer, Emmett, Teller	William W. Wendlandt	Hugo Rietveld
Tipus	Measurement method	Characterization method	Refinement method
Font seminal	Brunauer, S., Emmett, P. H., & Teller, E. (1938). Adsorption of gases in multimolecular layers. Journal of the American Chemical Society, 60(2), 309-319.	Wendlandt, W. W. (1986). Thermal Analysis (3rd ed.). John Wiley & Sons.	Rietveld, H. M. (1969). A profile refinement method for nuclear and magnetic structures. Journal of Applied Crystallography, 2(2), 65-71.
Àlies	BET analysis, nitrogen adsorption, surface area measurement	TGA, thermal gravimetry, thermogravimetry	Rietveld refinement, powder diffraction refinement
Relacionats	3	3	3
Resum	Brunauer-Emmett-Teller (BET) Surface Area Analysis is a technique for measuring the specific surface area of solids by analyzing their nitrogen adsorption isotherms. Developed by Brunauer, Emmett, and Teller in 1938, BET theory extends monolayer adsorption (Langmuir) to multilayer adsorption, enabling quantification of surface area of porous and powdered materials. It is the industry standard for characterizing catalysts, adsorbents, pharmaceuticals, and porous materials, providing critical data for performance prediction and quality control.	Thermogravimetric Analysis (TGA) is a thermal characterization technique that continuously measures mass loss or gain of a material as a function of temperature (or time at constant temperature). Developed systematically by William Wendlandt and colleagues in the 1960s, TGA identifies thermal transitions (evaporation, decomposition, oxidation, reduction) and quantifies composition of polymers, pharmaceuticals, ceramics, and other materials. The derivative signal (DTG) highlights transition temperatures. When combined with gas analysis (MS, FTIR), decomposition products are identified.	XRD Rietveld Refinement is a method for extracting detailed crystal structure information from powder diffraction data by comparing observed and calculated diffraction patterns through least-squares refinement. Developed by Hugo Rietveld in 1969, this technique enables determination of atomic positions, occupancies, thermal parameters, and phase fractions directly from powder data without requiring single crystals. It is the standard approach in materials characterization for structural analysis, phase identification, and quantification.