Holmium, Ho

Holmium is a chemical element with the symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a relatively soft and malleable silvery-white metallic element, which is stable in dry air at room temperature. A rare earth metal, it is found in the minerals monazite and gadolinite.

A trivalent metallic rare earth element, holmium has the highest magnetic moment (10.6µB) of any naturally-occurring element and possesses other unusual magnetic properties. When combined with yttrium, it forms highly magnetic compounds.

Holmium is a relatively soft and malleable element that is fairly corrosion-resistant and stable in dry air at standard temperature and pressure. In moist air and at higher temperatures, however, it quickly oxidizes, forming a yellowish oxide. In pure form, holmium possesses a metallic, bright silvery luster. Holmium oxide has some fairly dramatic color changes depending on the lighting conditions. In daylight, it is a tannish yellow color. Under trichromatic light, it is a fiery orange red, almost indistinguishable from the way erbium oxide looks under this same lighting. This has to do with the sharp emission bands of the phosphors, and the absorption bands of both oxides.

Technical Data
Symbol Ho Density (25°C)/gcm3: 8.78
Atomic number 67 Melting point / °C 1461
No. of naturally occurring isotopes 1 Boiling point / °C -2600
Atomic weight 164.9304 ΔHfus/kJmol-1  
Outer electron configuration 4f116s2 ΔHvap/kJmol-1 280
Metal radius (6-coordinate)/pm 176.2 ΔHf(monoatomic gas)/kJmol-1 301
Ionic radius(6-coordinate)/pm III 90.1 ΔH (hydration Ln3+)/kJmol1 3667
Ionization energy/kJmolI 574 Electrical resistivity  
Ionization energy/kJmolII 1139 (25°C)/jiohm cm 94
Ionization energy/kJmolIII 2221 Eo(M3+(aq)+ 3e- →M(s))/V  
Evaporation Techniques
Temperature (oC) >@ Vap. Pressure Techniques Remarks
10-8 Torr 10-6 Torr 10-4 Torr Electron Beam Crucible Coil Boat
650 Sublimes 770 Sublimes 950 Sublimes Good - Tungsten Tungsten & Tantalum  

Evaporation Materials
H2-5000-M pieces 1-3mm
H2-5001-M Ingot (Please ask for sizes)
H2-5002-M pieces 12mm and smaller

The foils are available in either rectangular or circular shape. Please enter width and length or diameter of the required foil.

Foil
H2-3003-F 0.004" (0.1mm)
H2-3007-F 0.008" (0.2mm)
Powder
H2-10000-P -40 mesh
Rods
H2-2000-R 0.250" (6.35mm)
H2-2001-R 0.500" (12.7mm)
Sheet
H2-4002-S 0.020" (0.508mm)
H2-4003-S 0.030" (0.762mm)
H2-4004-S 0.040" (1.0mm)