Néel relaxation

E326459

Néel relaxation is a magnetic relaxation process in which the magnetization of single-domain nanoparticles flips between energy minima due to thermal fluctuations without physical rotation of the particles.

All labels observed (1)

Label Occurrences
Néel relaxation canonical 3

How this entity was disambiguated

Statements (43)

Predicate Object
instanceOf magnetic relaxation process ⓘ
superparamagnetic relaxation mechanism ⓘ
anisotropyEffect relaxation time increases with increasing anisotropy constant ⓘ
assumes single-domain magnetic state of the particle ⓘ
characteristicFeature does not require physical rotation of the particle ⓘ
magnetization flips between energy minima ⓘ
competesWith Brownian relaxation ⓘ
dependsOn magnetic anisotropy constant ⓘ
magnetic anisotropy energy barrier ⓘ
particle volume ⓘ
temperature ⓘ
dominatesWhen magnetic anisotropy energy barrier is moderate ⓘ
particles are immobilized in a solid matrix ⓘ
drivenBy thermal fluctuations ⓘ
fieldOfStudy condensed matter physics ⓘ
materials science ⓘ
nanomagnetism ⓘ
hasEquation τ_N = τ_0 · exp(KV / k_B T) ⓘ
hasParameter K (anisotropy constant) ⓘ
T (absolute temperature) ⓘ
V (particle volume) ⓘ
k_B (Boltzmann constant) ⓘ
linked to: k_B

τ_0 (attempt time) ⓘ
τ_N (Néel relaxation time) ⓘ
historicalPeriod mid-20th century theoretical development ⓘ
leadsTo frequency-dependent AC magnetic susceptibility ⓘ
time-dependent decay of magnetization ⓘ
magnetizationChange occurs via coherent or quasi-coherent spin rotation ⓘ
mechanism thermally activated magnetization reversal ⓘ
namedAfter Louis Néel ⓘ
occursIn single-domain magnetic nanoparticles ⓘ
superparamagnetic particles ⓘ
relatedConcept Arrhenius law ⓘ
linked to: Arrhenius equation

energy barrier crossing ⓘ
relevantTo magnetic data storage stability ⓘ
magnetic hyperthermia ⓘ
magnetic nanoparticle imaging ⓘ
superparamagnetism ⓘ
sizeEffect relaxation time decreases with decreasing particle volume ⓘ
suppressedWhen temperature is very low compared to anisotropy energy barrier ⓘ
temperatureEffect relaxation time decreases with increasing temperature ⓘ
timeScale typically between 10^-12 s and many seconds depending on parameters ⓘ
usedIn analysis of blocking temperature in superparamagnets ⓘ

How these facts were elicited

Referenced by (3)

Full triples — surface form annotated when it differs from this entity's canonical label.

Louis Néel → knownFor → Néel relaxation ⓘ
Louis Néel → notableConcept → Néel relaxation ⓘ
Néel → hasDerivativeTerm → Néel relaxation ⓘ