From 269cd14abcdfa83bc67870835ffc5182aa410693 Mon Sep 17 00:00:00 2001
From: e3fm8 <wolf.widdra@physik.uni-halle.de>
Date: Tue, 27 Feb 2024 17:54:44 +0100
Subject: [PATCH] Plasma freq corrected
---
libhreels/dielectrics20.py | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
diff --git a/libhreels/dielectrics20.py b/libhreels/dielectrics20.py
index 52f3370..f3e6b60 100755
--- a/libhreels/dielectrics20.py
+++ b/libhreels/dielectrics20.py
@@ -4,25 +4,24 @@ import numpy as np
from scipy import constants
from scipy.integrate import cumulative_trapezoid
-def plasmaFrequency(n):
- '''Returns the plasma frequency for a given doping.'''
+def plasmaFrequency(n,eps_inf=1):
+ '''Returns the plasma frequency for a given doping n in charge/m³.'''
# Note that the function parameter is actually n/m, the charge carrier density
# over the band mass in units of electron mass in vacuum.
eps_0 = constants.value("vacuum electric permittivity")
e = constants.value('elementary charge')
m_e = constants.value('electron mass')
- w_P = np.sqrt(n*e*e/(eps_0*m_e)) #Hz
- w_P = w_P /1E+12 * 33.35641 #Hz -> THz -> cm^-1
- return w_P
-
-# def doping2chargecarrierdensity(doping): #use doping in percentage by mass, not volume
-# '''Returns the charge carrier density for a given doping in percentage.'''
-# return float(doping*3.31664067935517E+020*1E6) # doping[%] * charge carrier/cm^3 * 1E6 = n_e [m^-3]
-
-# def doping2plasmaFrequency(doping):
-# '''Returns the plasma frequency for a given doping.'''
-# n = doping2chargecarrierdensity(doping)
-# return plasmaFrequency(n)
+ # Careful: There is a factor of 2 pi between omega and nue:
+ # If the plasma oscillates in a polarisable medium eps_infinity will reduce the restoring fields
+ w_P = np.sqrt(n*e*e/(eps_0*eps_inf*m_e)) #
+ nue_P = w_P /1E+12 * 33.35641 /2 /np.pi #Hz -> THz -> cm^-1
+ return nue_P
+
+def chargeDensitySTO(x):
+ # Calculates the charge density per m^3 for SrTi_(1-x)Nb_xO_3
+ # assuming doping by one electron per Nb atom
+ vol = 3.91*3.91*3.91 * 1E-30 # unit cell volume in m^3
+ return x/vol
def loss(eps):
--
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