The evolving technology, and improved purity of commercially available neodymium oxide, was reflected in the appearance of neodymium glass that resides in collections today.

Neodymium ions in various types of ionic crystals, and also in glasses, act as a laser gain medium, typically emitting 1064 nm light from a particular atomic transition in the neodymium ion, after being " pumped " into excitation from an external sourceNeodymium doped glass slabs used in extremely powerful lasers for inertial confinement fusion.

Certain transparent materials with a small concentration of neodymium ions can be used in lasers as gain media for infrared wavelengths ( 1054 – 1064 nm ), e. g. Nd: YAG ( yttrium aluminium garnet ), Nd: YLF ( yttrium lithium fluoride ), Nd: YVO < sub > 4 </ sub > ( yttrium orthovanadate ), and Nd: glass.

Neodymium glass ( Nd: glass ) is produced by the inclusion of neodymium oxide ( Nd < sub > 2 </ sub > O < sub > 3 </ sub >) in the glass melt.

Usually in daylight or incandescent light neodymium glass appears lavender, but it appears pale blue under fluorescent lighting.

The first commercial use of purified neodymium was in glass coloration, starting with experiments by Leo Moser in November 1927.

The sharp absorption bands of neodymium cause the glass color to change under different lighting conditions, being reddish-purple under daylight or yellow incandescent light, but blue under white fluorescent lighting, or greenish under trichromatic lighting.

Since neodymium coloration depends upon " forbidden " f-f transitions deep within the atom, there is relatively little influence on the color from the chemical environment, so the color is impervious to the thermal history of the glass.

The original Moser recipe used about 5 % of neodymium oxide in the glass melt, a sufficient quantity such that Moser referred to these as being " rare earth doped " glasses.

Being a strong base, that level of neodymium would have affected the melting properties of the glass, and the lime content of the glass might have had to be adjusted accordingly.

Light transmitted through neodymium glasses shows unusually sharp absorption bands ; the glass is used in astronomical work to produce sharp bands by which spectral lines may be calibrated.

Neodymium is a component of " didymium " ( referring to mixture of salts of neodymium and praseodymium ) used for coloring glass to make welder's and glass-blower's goggles ; the sharp absorption bands obliterate the strong sodium emission at 589 nm.

Similarly, neodymium glass is becoming widely used more directly in incandescent light bulbs.

These lamps contain neodymium in the glass to filter out yellow light, resulting in a whiter light which is more like sunlight.

Moser also blended praseodymium with neodymium to produce " Heliolite " glass (" Heliolit " in German ), which was more widely accepted.

The light then passes four times through a circuit containing a neodymium glass amplifier similar to ( but much smaller than ) the ones used in the main beamlines, boosting the nanojoules of light created in the Master Oscillator to about 6 joules.

Other common host materials for neodymium are: YLF ( yttrium lithium fluoride, 1047 and 1053 nm ), YVO < sub > 4 </ sub > ( yttrium orthovanadate, 1064 nm ), and glass.

In the late 1920s, Leo Moser ( Moser glass-works Director General, 1916 to 1932 ) recombined praseodymium and neodymium in a 1: 1 ratio to create his " Heliolite " glass (" Heliolit " in Čeština ), which has color-changing properties between amber, reddish, and green depending on the light source.

It is a 60-beam ultraviolet frequency-tripled neodymium glass laser, which is capable of delivering 30 kilojoules at up to 60 terawatts onto a target less than 1 millimeter in diameter.

* The first type uses one of several solid media, including synthetic ruby and chromium in aluminum oxide, neodymium in glass ( Nd: glass ), and the most common type, crystal composed of yttrium aluminum garnet doped with neodymium ( Nd: YAG ).

The absorption bands of neodymium interact with the visible emission spectrum of mercury vapor, with the unfiltered shortwave UV light causing neodymium-containing minerals to reflect a distinctive green color.

Neodymium ions in various types of ionic crystals, and also in glasses, act as a laser gain medium, typically emitting 1064 nm light from a particular atomic transition in the neodymium ion, after being " pumped " into excitation from an external source

Because of the higher neodymium harmonic used, and the lower efficiency of frequency-doubling conversion, the fraction of IR power converted to 473 nm blue laser light in optimally configured DPSS modules is typically 10 – 13 %, about half that typical for green lasers ( 20 – 30 %).

As in all neodymium-doped laser crystals, the lasing action of Nd: YVO < sub > 4 </ sub > is due to its content of neodymium ions, which may be excited by visible or infrared light, and undergo an electronic transition resulting in emission of coherent infrared light at a lower frequency, usually at 1064 nm ( other transitions in Nd are available, and can be selected for by external optics ).

Some of this light is absorbed by the neodymium atoms in the glass, raising them to an excited state and leading to a population inversion which readies the lasing medium for amplification of a laser beam.

This is not a particularly efficient process, only a small amount of the energy stored in the glass is dumped into the beam ( about 20 %) and the " pumping " wastes a considerable amount of power by generating light that the neodymium cannot absorb.

Neodymium-iron-boron magnets can have up to 6 % of the neodymium substituted with dysprosium to raise the coercivity for demanding applications such as drive motors for hybrid electric vehicles.

The solid host materials are usually doped with an impurity such as chromium, neodymium, erbium or titanium ions.

The color of neodymium compounds — due to the Nd ( III ) ion — is often a reddish-purple but it changes with the type of lighting, due to fluorescent effects.

Neodymium is a quite electropositive element, and it reacts slowly with cold water, but quite quickly with hot water to form neodymium hydroxide:

Naturally occurring neodymium is a mixture of five stable isotopes, < sup > 142 </ sup > Nd, < sup > 143 </ sup > Nd, < sup > 145 </ sup > Nd, < sup > 146 </ sup > Nd and < sup > 148 </ sup > Nd, with < sup > 142 </ sup > Nd being the most abundant ( 27. 2 % of the natural abundance ), and two radioisotopes, < sup > 144 </ sup > Nd and < sup > 150 </ sup > Nd.

In all, 31 radioisotopes of neodymium have been detected, with the most stable radioisotopes being the naturally occurring ones: < sup > 144 </ sup > Nd ( alpha decay with a half-life ( T < sub > ½ </ sub >) of 2. 29 × 10 < sup > 15 </ sup > years ) and < sup > 150 </ sup > Nd ( double beta decay, T < sub > ½ </ sub > = 7 × 10 < sup > 18 </ sup > years, approximately ).

As with neodymium glasses, such minerals change their colors under the differing lighting conditions.

Small and large volcanic eruptions produce lava with different neodymium isotope composition.

Likewise, due to this high magnetic capacity per weight, neodymium is used in the electric motors of hybrid and electric automobiles, and in the electricity generators of some designs of commercial wind turbines ( only wind turbines with " permanent magnet " generators use neodymium ).

In 1902, Bohuslav Brauner suggested there was an element with properties intermediate between those of the known elements neodymium ( 60 ) and samarium ( 62 ); this was confirmed in 1914 by Henry Moseley who, having measured the atomic numbers of all the elements then known, found there was no element with atomic number 61.

* Certain crystals, typically doped with rare-earth ions ( e. g. neodymium, ytterbium, or erbium ) or transition metal ions ( titanium or chromium ); most often yttrium aluminium garnet ( YAG ), yttrium orthovanadate ( YVO < sub > 4 </ sub >), or sapphire ( Al < sub > 2 </ sub > O < sub > 3 </ sub >);

Gadolinite, sometimes also known as Ytterbite, is a silicate mineral which consists principally of the silicates of cerium, lanthanum, neodymium, yttrium, beryllium, and iron with the formula ( Ce, La, Nd, Y )< sub > 2 </ sub > FeBe < sub > 2 </ sub > Si < sub > 2 </ sub > O < sub > 10 </ sub >.

A typical composition includes approximately 50 % cerium and 25 % lanthanum, with small amounts of neodymium and praseodymium.

Monazite-derived Mischmetal typically was about 48 % cerium, 25 % lanthanum, 17 % neodymium, and 5 % praseodymium, with the balance being the other lanthanides.

The most common decay mode for 18 isotopes with mass numbers higher than praseodymium-141 is β < sup >−</ sup > decay, primarily forming neodymium isotopes ( 60 protons ) as decay products.