Yttrium ionization energy

The values of the first four ionization energies for the lanthanides (and yttrium) are listed in Table 2.2. 

For all their usefulness, gas lasers are very inefficient lasers, with normally much less than 0.1 per cent conversion of electrical energy into laser light. A very widely used solid-state laser material is Nd YAG (and various similar doping/host material combinations). The abbreviation Nd YAG stands for neodymium atoms (Nd) being implanted in an yttrium aluminium garnet crystal host (Y3AI5O12). These implants, in the form of triply ionized neodymium Nd, form the actual active laser medium. 

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