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A cloud‐hosted web‐based software application, nmfMapping, for carrying out a non‐negative matrix factorization of a set of powder diffraction or atomic pair distribution function datasets is described. This application allows structure scientists to find trends rapidly in sets of related data such as from in situ and operando diffraction experiments. The application is easy to use and does not require any programming expertise. It is available at https://pdfitc.org/. [ABSTRACT FROM AUTHOR]

Temperature is a ubiquitous environmental variable used to explore materials structure, properties and reactivity. This article reports a new paradigm for variable‐temperature measurements that varies the temperature continuously across a sample such that temperature is measured as a function of sample position and not time. The gradient approach offers advantages over conventional variable‐temperature studies, in which temperature is scanned during a series measurement, in that it improves the efficiency with which a series of temperatures can be probed and it allows the sample evolution at multiple temperatures to be measured in parallel to resolve kinetic and thermodynamic effects. Applied to treat samples at a continuum of temperatures prior to measurements at ambient temperature, the gradient approach enables parametric studies of recovered systems, eliminating temperature‐dependent structural and chemical variations to simplify interpretation of the data. The implementation of spatially resolved variable‐temperature measurements presented here is based on a gradient‐heater design that uses a 3D‐printed ceramic template to guide the variable pitch of the wire in a resistively heated wire‐wound heater element. The configuration of the gradient heater was refined on the basis of thermal modelling. Applications of the gradient heater to quantify thermal‐expansion behaviour, to map metastable polymorphs recovered to ambient temperature, and to monitor the time‐ and temperature‐dependent phase evolution in a complex solid‐state reaction are demonstrated. [ABSTRACT FROM AUTHOR]