page_title: Zone melting
hierarchical_section_title: Zone melting
caption_attribution_description: Deutsch: Ein hochreiner (99,999&#160;% = 5N) Tantal-Einkristall, hergestellt nach dem Zonenschmelzverfahren, einige einkristalline Tantalbruchstücke, sowie für den Größenvergleich ein reiner (99,99&#160;% = 4N) 1 cm3 Tantal-Würfel. English: A high purity (99.999&#160;%) tantalum single crystal, made by the floating zone process, some single crystalline fragments of tantalum, as well as a high purity (99.99&#160;% = 4N) 1 cm3 tantalum cube for comparison. Français&#160;: Un monocristal de tantale de haute pureté (99,999&#160;%), obtenu par la Méthode de la zone fondue. Pour comparaison, on peut aussi voir sur l'image des fragments monocristallins de tantale, ainsi qu'un cm3 du même élément pur à 99,99&#160;% et anodisé.
context_page_description: Zone melting is a group of similar methods of purifying crystals, in which a narrow region of a crystal is melted, and this molten zone is moved along the crystal. The molten region melts impure solid at its forward edge and leaves a wake of purer material solidified behind it as it moves through the ingot. The impurities concentrate in the melt, and are moved to one end of the ingot. Zone refining was invented by John Desmond Bernal and further developed by William Gardner Pfann in Bell Labs as a method to prepare high purity materials, mainly semiconductors, for manufacturing transistors. Its first commercial use was in germanium, refined to one atom of impurity per ten billion, but the process can be extended to virtually any solute-solvent system having an appreciable concentration difference between solid and liquid phases at equilibrium. This process is also known as the float zone process, particularly in semiconductor materials processing.
context_section_description: Zone melting (or zone refining or floating-zone process or travelling melting zone) is a group of similar methods of purifying crystals, in which a narrow region of a crystal is melted, and this molten zone is moved along the crystal. The molten region melts impure solid at its forward edge and leaves a wake of purer material solidified behind it as it moves through the ingot. The impurities concentrate in the melt, and are moved to one end of the ingot.  Zone refining was invented by John Desmond Bernal and further developed by William Gardner Pfann in Bell Labs as a method to prepare high purity materials, mainly semiconductors, for manufacturing transistors. Its first commercial use was in germanium, refined to one atom of impurity per ten billion, but the process can be extended to virtually any solute-solvent system having an appreciable concentration difference between solid and liquid phases at equilibrium.  This process is also known as the float zone process, particularly in semiconductor materials processing.
caption: A high-purity (5N) tantalum single crystal, made by the floating-zone process (cylindrical object in the center)
exif: {"Image Make": "Canon", "Image Model": "Canon EOS 5D Mark II", "Image Orientation": "Horizontal (normal)", "Image XResolution": "300", "Image YResolution": "300", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS4 Windows", "Image DateTime": "2010:05:29 22:30:47", "Image Artist": "Heinrich Pniok", "Image YCbCrPositioning": "Centered", "Image Copyright": "Copyright: Heinrich Pniok", "Image ExifOffset": "292", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "1154", "Thumbnail JPEGInterchangeFormatLength": "3496", "EXIF ExposureTime": "1/6", "EXIF FNumber": "10", "EXIF ExposureProgram": "Aperture Priority", "EXIF ISOSpeedRatings": "200", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2010:05:29 10:17:28", "EXIF DateTimeDigitized": "2010:05:29 10:17:28", "EXIF ComponentsConfiguration": "YCbCr", "EXIF ShutterSpeedValue": "21/8", "EXIF ApertureValue": "53/8", "EXIF ExposureBiasValue": "2/3", "EXIF MeteringMode": "Spot", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "100", "EXIF SubSecTime": "906", "EXIF SubSecTimeOriginal": "20", "EXIF SubSecTimeDigitized": "20", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "4937", "EXIF ExifImageLength": "2991", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "1028", "EXIF FocalPlaneXResolution": "5616000/1459", "EXIF FocalPlaneYResolution": "1872000/479", "EXIF FocalPlaneResolutionUnit": "2", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard"}