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Lanthanide

Gadolinium

Gadolinium is a silvery lanthanide, first identified in 1880, that stands out among the rare earths for being magnetic near room temperature. It's best known today as the basis for the contrast agents used in MRI scans, and it's named after the pioneering Finnish chemist Johan Gadolin.

Group · Period
— · 6
At room temp
solid
Melts at
1586 K
Density
7.9 g/cm³
Discovered
1880

Uses

Gadolinium’s best-known application is in medicine: compounds containing gadolinium are used as contrast agents for magnetic resonance imaging, injected into patients to make blood vessels, organs, and abnormal tissue stand out far more clearly on the scan. This works because gadolinium ions are strongly paramagnetic, altering how surrounding water molecules respond to the scanner’s magnetic field.

Gadolinium is also unusual in being ferromagnetic just below room temperature, a property researchers have explored for magnetic refrigeration, a cooling technique that avoids the gases used in conventional refrigerators. Beyond that, its ability to absorb neutrons effectively makes it useful in neutron radiography and in some nuclear reactor shielding and control applications.

History

Gadolinium was identified spectroscopically in 1880 by Swiss chemist Jean Charles Galissard de Marignac, who detected it in samples derived from the mineral samarskite, and it was isolated in a more purified form a few years later by Paul-Émile Lecoq de Boisbaudran. It’s named not after a place but after Johan Gadolin, a Finnish chemist whose late-18th-century study of a rare-earth mineral — later named gadolinite in his honor — helped kick off the long process of discovering the rare-earth elements in the first place.

Fun facts

  • Gadolinium compounds are injected into patients before many MRI scans to make internal structures show up more clearly.
  • Gadolinium is ferromagnetic — meaning it can act like a magnet — but only below about 20°C, close to room temperature, which is unusual among the elements.
  • It's named after Johan Gadolin, a Finnish chemist who studied the rare-earth mineral gadolinite decades before gadolinium itself was identified.

Frequently asked questions

Why is gadolinium used in MRI scans?

Gadolinium ions are strongly paramagnetic, meaning they respond powerfully to magnetic fields, which changes how nearby water molecules behave in an MRI scanner. Doctors inject a safely bound gadolinium compound, called a contrast agent, to make blood vessels, tumors, and other soft tissues show up with much sharper contrast on the scan.

Is gadolinium magnetic like iron?

In a sense, yes — gadolinium is one of the few elements that's ferromagnetic, meaning it can hold a magnetic field the way iron does. But it only behaves that way below roughly room temperature; above that point it loses its magnetism, which is very different from iron, which stays magnetic at much higher temperatures.

Is gadolinium named after a place, like many other lanthanides?

No — unlike ytterbium or terbium, which take their names from the village of Ytterby, gadolinium is named after a person: Johan Gadolin, a Finnish chemist who first analyzed the mineral gadolinite in the late 1700s. That mineral later gave up several other rare-earth elements too.

Compounds

2 notable compounds containing Gd

  • GdCl3halide

    Gadolinium(III) chloride

    A white, deliquescent gadolinium salt used throughout gadolinium chemistry as the entry point for making other gadolinium compounds, including its highly paramagnetic complexes.

    Used for: Laboratory precursor for gadolinium coordination and contrast-agent chemistry

  • Gd2O3oxide

    Gadolinium(III) oxide

    A white, high-melting rare-earth oxide that is the standard commercial form of gadolinium and a common host lattice for phosphor and ceramic applications.

    Used for: Starting material for gadolinium-based MRI contrast agent compounds

Isotopes

39 known isotopes

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IsotopeNatural abundanceHalf-lifeDecay modeMass excessBinding energy / nucleonDecay width
Gd-152 0.2% 1.08E14 Y Alpha decay (100%) -74,707.3 keV 8,233.4 keV 1.34 × 10-37 eV
Gd-154 stable 2.18% Stable -73,706.36 keV 8,224.8 keV
Gd-155 stable 14.8% Stable -72,070.3 keV 8,213.25 keV
Gd-156 stable 20.47% Stable -72,535.33 keV 8,215.33 keV
Gd-157 stable 15.65% Stable -70,823.9 keV 8,203.51 keV
Gd-158 stable 24.84% Stable -70,689.97 keV 8,201.82 keV
Gd-160 stable 21.86% Stable -67,942.06 keV 8,183.02 keV
Show all 39 isotopes
Gd-134 Unknown -41,530 keV 8,008 keV
Gd-135 1.1 s Electron capture / beta-plus decay (100%), ECP (2%) -44,250 keV 8,028 keV 4.15 × 10-16 eV
Gd-136 200 ns Unknown -49,090 keV 8,064 keV 2.28 × 10-9 eV
Gd-137 2.2 s Electron capture / beta-plus decay (100%), ECP -51,214 keV 8,080 keV 2.07 × 10-16 eV
Gd-138 4.7 s Electron capture / beta-plus decay (100%) -55,660 keV 8,112 keV 9.71 × 10-17 eV
Gd-139 5.8 s Electron capture / beta-plus decay (100%), ECP (0%) -57,632 keV 8,126 keV 7.87 × 10-17 eV
Gd-140 15.8 s Electron capture / beta-plus decay (100%) -61,782.28 keV 8,154.98 keV 2.89 × 10-17 eV
Gd-141 14 s Electron capture / beta-plus decay (100%), Beta-plus, proton emission (0.03%) -63,224.23 keV 8,164.61 keV 3.26 × 10-17 eV
Gd-142 70.2 s Electron capture / beta-plus decay (100%) -66,959.52 keV 8,190.26 keV 6.50 × 10-18 eV
Gd-143 39 s Electron capture / beta-plus decay (100%) -68,231.31 keV 8,198.32 keV 1.17 × 10-17 eV
Gd-144 4.47 m Electron capture / beta-plus decay (100%) -71,759.51 keV 8,221.94 keV 1.70 × 10-18 eV
Gd-145 23.0 m Electron capture / beta-plus decay (100%) -72,926.63 keV 8,228.95 keV 3.31 × 10-19 eV
Gd-146 48.27 d Electron capture / beta-plus decay (100%) -76,085.82 keV 8,249.51 keV 1.09 × 10-22 eV
Gd-147 38.06 h Electron capture / beta-plus decay (100%) -75,356.93 keV 8,243.34 keV 3.33 × 10-21 eV
Gd-148 71.1 Y Alpha decay (100%) -76,269.42 keV 8,248.34 keV 2.03 × 10-25 eV
Gd-149 9.28 d Electron capture / beta-plus decay (100%), Alpha decay (0.00043%) -75,127.17 keV 8,239.49 keV 5.69 × 10-22 eV
Gd-150 1.79E+6 Y Alpha decay (100%) -75,764.05 keV 8,242.61 keV 8.08 × 10-30 eV
Gd-151 123.9 d Electron capture (100%), Alpha decay (8e-7%) -74,188.92 keV 8,231.04 keV 4.26 × 10-23 eV
Gd-153 240.4 d Electron capture (100%) -72,882.94 keV 8,220.42 keV 2.20 × 10-23 eV
Gd-159 18.479 h Beta-minus decay (100%) -68,561.86 keV 8,187.62 keV 6.86 × 10-21 eV
Gd-161 3.66 m Beta-minus decay (100%) -65,506.14 keV 8,167.19 keV 2.08 × 10-18 eV
Gd-162 8.4 m Beta-minus decay (100%) -64,280.72 keV 8,159.04 keV 9.05 × 10-19 eV
Gd-163 68 s Beta-minus decay (100%) -61,388.59 keV 8,140.76 keV 6.71 × 10-18 eV
Gd-164 45 s Beta-minus decay (100%) -59,693.69 keV 8,130 keV 1.01 × 10-17 eV
Gd-165 10.3 s Beta-minus decay (100%) -56,525.78 keV 8,110.44 keV 4.43 × 10-17 eV
Gd-166 4.8 s Beta-minus decay (100%) -54,370.93 keV 8,097.23 keV 9.50 × 10-17 eV
Gd-167 4.26 s Beta-minus decay (100%) -50,775.73 keV 8,075.54 keV 1.07 × 10-16 eV
Gd-168 3.03 s Beta-minus decay (100%) -48,150 keV 8,060 keV 1.51 × 10-16 eV
Gd-169 0.75 s Beta-minus decay (100%), Beta-minus, neutron emission -43,890 keV 8,035 keV 6.08 × 10-16 eV
Gd-170 0.41 s Beta-minus decay (100%), Beta-minus, neutron emission -40,850 keV 8,017 keV 1.11 × 10-15 eV
Gd-171 Beta-minus decay (100%), Beta-minus, neutron emission -36,210 keV 7,990 keV
Gd-172 Beta-minus decay (100%), Beta-minus, neutron emission -32,970 keV 7,972 keV